They're running a small business where they need to get paid for their time and effort.
The things you're complaining about are the things that YouTube forces them to do in order GET paid.
They get paid for subscribers (ad revenue).
If subscribers don't interact with the channel (likes, comments, etc...) they run the risk of having subscribers deleted for being "inactive".
They are trying to help out other content-creators by networking, and sometimes sharing viewers. In the Destiny community there is a tradition of "raiding" podcast or twitch streams of other creators so that people from one group of fans gets introduced to that content creators work.
But if you listen to the creators, they make it pretty clear that they resent having to be this "in your face" with all this stuff, simply to get paid.....and REALLY resent the bullshit that YouTube is currently playing with their livelihoods.