I comment on people's post all the time just because I know they'll upvote. Might be a little "greedy", but it gets my name out there and is a way I can almost guarantee rewards for the time I put into steemit.
Why I almost always, as you pointed out, upvote as many comments on my post as I can unless I'm trying to rebuild my steempower.
You really comment a lot, I think on almost all my posts :)
Thanks for that buddy :)