I'd say it depends on the people playing more than the games itself, and that's true for any intellectual pursuit. I know plenty of people in my class who read the same material I did for our exams, and didn't grasp any of the intellectual points that I thought were bloody obvious. In the same vein, someone like me is a lot more likely to read deeper meaning into a game (whether it's there or not is up for debate) whereas someone who's only just in it for killstreaks and gore might consciously ignore anything deeper and get little to nothing out of it.
For example, I thought the story in Modern Warfare 2 was a quite obvious allegory for how the USA got into the War in Iraq, and so I thought the story was quite good and surprisingly intellectually engaging for a war game, but a lot of people didn't get the same message I did and, consequently, have called the story a pile of bullshit, maybe just because it's hard to think about the deeper context of a game when you're trying not to die every five seconds.
See what I mean? Some people are only in video games for mindless entertainment, and, if that's their prerogative, it's fine by me, but that doesn't make the game or gaming itself a mindless exercise; it just means that those people don't want to learn, or think about it. I mean, on even the most basic level, reading and mathematics have traditionally been a huge component of video games, back in the days of text-dialogue and health meters, but, beyond that, I find that video games are increasingly trying to offer more complex moral ideas and questions in their stories than I see in most mainstream media today, even if they're not always successful.