I almost never like stuff on facebook and I usually only comment for humor - I use facebook only because of the chat feature to stay connected to those of my friends that don't use Telegram.
On Steem, on the other hand, I feel really productive when I comment and upvote other peoples work. I like the atmosphere much more around here and I feel that people actually care about comments and votes - not just for financial reasons.
I joined Steem for the investment aspect, at first, but there is so much more to it - at least on my opinion.