I'm going to assume this is about revenue from the mostly unrelated ads played before the videos in question, and not the advertisement of the games being played in the videos themselves.
This would've been a major issue if the YouTubers actually charged money for viewing their LPs. But this is about ad revenue, which is usually generated by viewers voluntarily clicking on ads to support the YouTuber. There's a lot of folks out there recording themselves playing video games, and only a few (most notably, a certain Swedish gentleman) gained widespread popularity due to their genuinely entertaining commentary and accessible humor (which is subjective, of course). They get a ton of views on their videos, the viewers click on ads, the LetsPlayers get money.
Now, if a game developer like Fish decided he deserved some of that advertising money because he believed it was his product that was drawing in the viewers, he'd find himself in the middle of a ridiculous debate over how much money he's entitled to, i.e. how much of the video's "click bait potential" is attributed to the source material. Dividing the revenue for each video between the YouTuber with his reputation, appearance, humor etc. and the developer with his... well, his game, would be virtually impossible, and establishing a fixed "cut" of the money for every video would be unfair to both parties. Phil Fish wants some of that $$$ that people are earning while playing HIS game, but it's hardly his game that's making the money here.
The problem, for me, lies in the entire ad system on YouTube. I don't like advertising, I never liked it, and the bullshit YouTube's pulling is horrible. It's not even sponsoring, since the 'Tubers have no say in what ads are shown on their videos. I personally consider it a shameful way to make money, and wouldn't do it myself. If you think you should get paid for your content, fucking sell it! Ask for donations, start a Kickstarter campaign to buy some new equipment, whatever. Except if you want to sell something, it's got to be 100% yours. And these big YouTube stars are getting paid for their views, not their content.
I don't have a point to prove. Fish is a greedy, oversensitive dick, advertising sucks. I'm out.