I've been watching the YouTube drama. It really feels like something overcorrected (as opposed to all the notices being intended effect of new terms.) I even saw a screenshot on twitter of an innocent video about a video game being bad getting de-monetized(!?)(Possibly Nintendo stuff you referenced above.)
This leads me to think they'll pull back a bit, and don't have total control of the system, and de-monetization will be less aggressive. I've also seen chatter that disputing stuff is pretty effective/responsive.
This doesn't mean I think we should all relax and put all our eggs in one basket. Just that I think this spike of chaos will settle down.
On to your main point: Creative people definitely need to be able to distribute their risk/investment across a bunch of platforms (and some Internet romantics would even say, "Host it yourself, own your infrastructure, etc.") I'm in a camp where I think creative people should be allowed to not think about distribution/technical/marketing (if they want), so I get the appeal of YouTube's platform. Those creators can focus just on making videos. (And it's been amazing to watch creators "grow into" caring about marketing/distribution/business, as they get big, but only because they were able to focus on creating in the early stages.)
YouNow (very popular, but mostly with very young people, so unknown to many) is a social video platform not worlds apart from a consumer-friendly steem. Users can gift each other virtual goods/currency, (as opposed to less efficient sliver of ad rev share). So lots of creators are getting well paid over there, without requiring the huge audiences it requires to make sizable money on YouTube.
As soon as I saw steem, I thought of YouNow. (YouNow being a possibly model for how simple the steem experience could become.)
Anyway, if you or any lurkers are interested in social platform monetization patterns, I track them and wrote some stuff up.
UPDATE: it's looking more and more like the only thing that changed was the notification style, not the policy. These videos were already demonetized, just silently.(https://medium.com/internet-creators-guild/youtube-de-monetization-explained-44464f902a22#.q4npv7iyi)
They also still get YouTube Red revenue.
It is an overreaction, basically companies who post ads have a say on what kind of content their ads are placed with. Its actually perfectly sensible.
However, Steemit has a similar problem in the form of a dependence on whale votes. The equivalent would be to cry that giving whales a right to vote on what they like is a form of censorship.