YouTube's financial incentivization optimizes towards crappy Minecraft videos moreso than high production value content, since they started rewarding time spent watching over total number of views/subscribers. Such videos are the easiest to create in terms of effort per posted minute of video that is attractive to (enough) viewers.
One of the popular groups (Game Grumps) even explicitly have said so in their videos. Arin/Egoraptor is an animator, but animations are hard work to create and aren't rewarded financially on YouTube anymore, so he specifically went into something where he could make money (doing Let's Plays).
Basically, what you see popular on YT is not because of what people are passionate about, but rather what YT's schemes optimize people to do with their financial carrot.
But copyright just establishes title, and provides the right to recover additional damages from infringers if you register it with Congress. It doesn't set any sort of price structure, so it's perfectly OK to buy the rights to someone's work $1 if you can persuade them to sell at that price (as many session musicians have found out the hard way).
* in passing, I noticed recently that multi-hour videos of rainfall are crazy popular on YT, presumably because of their use as a sleep aid.