This is true across the web. Not only do some people not read through it all and not understand the nuance even if they did read all of it, they also tend to play follow the leader and downvote when others already have instead of taking a minute or two out of their day and deciding for themselves.
I really wish we could get away from the up/down votes. Despite knowing better and honestly not giving a flying fuck, I find myself obsessed with it at times and it's not healthy. As much as I dislike the emoticons that have taken over, I'd almost prefer that. Use hearts or smiley faces or something and show the actual ratio of up/down, ie 5 hearts and 5 frowny face or whatever.