A lot of good questions here Meno.
I think you're right that they're clueless with how this particular platform works.
Platforms like Instagram require daily posts and story posts.
Facebook is kinda similar, but the posts don't need to be daily.
Youtube doesn't work well that way. It's more like watching your favourite TV show. The Youtuber post must be at least once per week, but probably not more than a few per week. Of course, that greatly depends upon the type of content and audience, but if a Youtuber has become successful, it is because they've spent years working that platform (or they made a video that went viral or both) whilst working intimately with the analytics.
It is vastly different to Steemit and I am guessing that many of them don't want to start from scratch again or perhaps their model of business strategy excludes spending so much time on interaction, rather than high-quality content creation.
This is where I think there are potential flaws in Steemit.
If it leans too much on interaction then it inspires lower quality content creation. Yet, if there's not enough interaction then you lose your audience.
I'm still excited by Steemit, but the interactivity, whilst a lot of fun, can be a distraction from attaining goals of making high quality content.
I personally want to find a balance somewhere in the middle of those two poles.
I can understand why a Youtuber wouldn't feel like starting from scratch.
That could be rather despiriting.
But it might also be laziness and with the nature of how quickly platforms can and will get replaced by newer platforms in this digital era (and that process will speed up), it is probably dangerous to get lazy with adaptation.
They'll probably find themselves coming back to Steemit or something similar and realising that they'd have to start from scracth anyway if they wish to keep up with the changing times.
But if they are already earning good money for their efforts on Youtube, they probably don't yet see the benefits of dropping the ball on that platform just yet in order to adopt a vastly more time consuming platform like Steemit.
Anyway, they're some of my thoughts inspired by your thoughts...
:)
Blissful blessings and smiles
in joy
Nathan
NK