I think you have a good point with the interactions. It is very important that people actually stay on the site and comment and read other's stuff, or else it's just a big place where everyone posts their own stuff and log outs, which is not good for the long-term.
Lots of people actually upvote good comments, so there is actually a pretty nice amount of money to be made from interacting, so I don't get why more people don't do it. One issue is probably that it is difficult to find good content on Steemit unless you know where to look.
What is precisely your definition of earning a nice amount with interaction?
I think it is pretty difficult to earn more than 1SBD per week. although I should probably be a bit less critical of I want to earn more. But my goal is not to earn only money.
I think most new steemonians get discouraged by the fact it is really difficult to get noticed. Mostly you have merely any followers, no views for your posts and you don't earn any money.
Even if you earn a few cents, the steemit system seems unfair. Because the whales easily get richer and richer and minnows are almost impossible to close this gap.
My definition of a nice amount from comments is probably $5+ each day, unless you write a whole lot of comments. I mean, no one will get rich from comments, but it should be entirely possible to make a few SBD every day from it.