It's a combination of marketing and fear. At the end of the day SJWs are pretty well organized and the resistance to them is fairly new. Industries take a long time to change, so now that the SJW domination is paying off your seeing the results of their campaigns of intimidation. It will take a few years to see if GG has any real effect on the landscape given the dev time for games. That said given that as a general rule SJWs will harass you and GG for the most part only goes after SJWs but doesn't turn it's attention towards companies that cave in to a SJW agenda, right now it's easier for companies to simply do what the SJWs want. What's more given how entrenched SJWs are into the media, con circuit, etc... and that companies need that support it ads to the attitudes of appeasement.
To be honest when you get down to it minorities have been represented well in games and geek media for a very long time, which is part of why people are sick of SJWs. Minorities are just that, minorities, which means they have a minority prescence and aren't going to be in every work. The SJW movement has increasingly been about putting minorities into everything as opposed to simply letting creators do it when they want to. What's more it's increasingly about waving it in front of everyone's face, more than it simply being there. That's one of the reasons why this is an unwinnable situation, which I believe is what SJWs want on some levels so they have something to constantly fight about and feel relevant. Basically you can't have a character who just happens to be a homosexual and acts normal because then it would just be a person, rather you need to know the character is homosexual, it needs to be paraded out, and by being a normal person you need to have him jump up on a soap box and spend at least 5 minutes of game time screaming "I am GAAAAAY". What's more if a game company doesn't put as much work into a gay romance, or even doesn't have one, when there are heterosexual ones, god help them nowadays for not wanting to spend resources on something only a tiny group of people will appreciate, and mostly exists because SJWs have something to feel smug about.
To put things into a more direct perspective, not that this message is going to go over with well here anyway, we've already had LGBT fighting game characters. Of course none of them were as heavily promoted as Mortal Kombat's roof screaming "we have a gay fighter!". For example Guilty Gear has had "Bridget" famously as part of the roster for quite a while, to say nothing of "Poison" who can be defined as anything from a post-op transsexual to a guy with his junk pinned up depending on what version of the game it is, Morrigan from Dark Stalkers is infamously bi-sexual including some apparently canon sex-scenes from the artwork with Lillith who is her sister (and also part of her soul), she also hits on Etna in "Cross Edge". This is to say nothing of numerous other fighting games where apparently there have been decent numbers of gay characters where it wasn't so obvious, I think it's "King Of Fighters" where there was at one point a showdown over "Andy Bogard" between some sexy ninja who loves him and some gay guy who also wound up being in love with him and characters which have been defined as going every which way, but none of that really comes out in the games which are about you know.. fighting. The point is that while there are not a lot of them compared to the straight dudes (and dudettes) you'll see fighting games have as a general rule been about as diverse as anything, considering minorities being well... minorities. The games still have a heavy Japanese bias as a whole since most of them are developed in Japan, American involvement to the extent it is present being because of Japan's weird love/hate relationship with the west, and America in particular.
People also tend to forget that homosexuality was famously an issue in "Phantasmagoria 2: A Puzzle Of The Flesh", and if you dig you'll find there is more of it throughout gaming and geek media than people want to give credit to, the problem being mostly that it was understated which is supposedly what people want, but apparently do not since being understated does not count when going into discrimination by the industry.
Basically Mortal Kombat having a gay character is noteworthy only because they decided to shout it from the roof tops for the SJWs, and the odd thing is that this character's big thing seems to be simply that he's gay, as opposed to some of the other characters I've mentioned who have much more involved roles in their varies series. For example Morrigan is a HUGE part of "Dark Stalkers" (and it's various other names) and some have even argued she's the hero of the game, not Dimitri. She's a bi-sexual to the extreme if you look into her (she's a succubus, duh) and the creators did a bit of pervy artwork reinforcing this. Felicia might arguably be as well. It's just it was never "beat you over the head" obvious because in the games themselves she didn't exactly run up and yell "I'm bi-sexual" or start making out with a girl (though there is a scene of her in Llith in one of the PSP games during the closing credits that... uh well, I'm sure most have seen it nowadays). Poison's gender identity has been a topic of discussion for years, but didn't rise to the point of major spectacle so I guess it didn't count. Bridget has been around for a long time now and is another big one I mentioned for being well know but I guess doesn't count because... reasons, and that one is even well written into the game's backstory and lore.
Likewise when it comes to another "oppressed" group which is women, nowadays you see SJWs about negative portrayals of women as "simply being sex objects and goals to be obtained" but really you have to dig to find any that fit that definition. Back during the late 1980s and early 1990s there was some truth to this. However even before SJWs were a thing you saw that changing. To be honest other than going back to extreme classic characters like Zelda, Princess Peach, and others in their original games I simply can't think of many dedicated "Damsels in Distress" that aren't subverting an old trope. Many of those same classic characters also received their own games and agency within them. Princess Peach was a passive objective in "Mario" but she's also had her own games. For the most part you see people like Anita Sarkeesian bringing up games like those, or even double dragon, in many cases decades after their real relevancy. Even the artwork she stole of characters like "The Delightful Daphne" are of truly ancient games, and to be honest even at the time of "Daphne" they were making fun of the entire idea since "Dragon's Lair" and "Space Ace" were absurdist comedies. Looking back today I am hard pressed to find many female characters that have no real characterization other than to be rescued at all, and truthfully even going back as far as the mid-1990s it's not difficult to think of female video game characters that were kicking some serious butt or had a strong role in their games. Indeed the mid-1990s saw a rise of REAL feminism (Wave 1 feminism) in geek culture, as this was the time period you had tons of sexy babes kicking butt alongside the boys, being able to be strong without giving the rest of it up. Pretty much every company was working to create their own stable and video games seemed to reflect this. To make a point faux-feminism has to try and say that sexy looking women are demeaning to even begin to start making cases... of course that's never stopped SJWs, it can be hilarious at times though to see people in some cases fighting battles that were won before they were even born.
Ahh well, enough rambling. I don't expect a lot of agreement (and I'm not going to get into any major arguments over this).