The problem is not with the rules limiting the content creator from using profanity and showcasing 18+ games. The problem is in the creator themselves.

Rules are rules. Youtube is not saying that content cannot be posted on their service. They are simply stating that if you want to make money off your content then you won't do/show that stuff. Simple.

I understand that making videos is not easy or simple. I also understand people love to be compensated for their time and effort when creating something.

Youtube is bending to the rules set by advertisers. Simple. If the content creators want to create videos for fun and use profanity and 18+ footage then go ahead. No one is stopping you. You just won't be able to monetize through Youtube.

I think the reason gaming Youtube "personalities" are dying is that the field is too crowded. Early on there weren't a lot of people doing it, those that were were doing it for the love of showcasing certain games. They got popular and so it caught the attention of companies like Nintendo and many indie developers (believe me, I have more trouble monetizing a video from an indie developer than commercial developers).

Still, the scene is overcrowded right now. Everyone wants in and everyone wants ad revenue for their videos. That creates demand on the wrong side of the advertising spectrum, it puts too much power in the hands of the advertiser and we get rules like this.