1) The share button is an upvote.
2) Follower counts make you cool.
The problem is we're largely social beings and that by definition involves interaction with other people.. When you post a link or comment on something, what clues or evidence do you receive that someone else is affected by your action? Literally nothing but another comment or that ubiquitous 'Like' button; no nuance just a binary or at best 3-state notification good/bad/nothing.
It doesn't matter whether it's Like, upvote/downvote or share - it's one of only two feedback mechanisms and we have millennia of behavioral and social conditioning that control our response. We have masses of non verbal cues that we pick up on when we meet people physically but online there is virtually nothing. It doesn't matter whether you consciously eschew it or not, there's plenty going on under that mental veneer that you don't consciously control.
Of course... we're above all that crass vulgarity - I'm just talking about those other poor pavlovian schmucks. ;)
goobster share it and then leave a comment. Let others know you're interested and what you think - otherwise what's the fucking point?