My experience tells me that (1) people certainly do downvote simply for disagreement and (2) it's simply not much worth worrying about. The Guidelines seems to

My experience tells me that (1) people certainly do downvote simply for disagreement and (2) it's simply not much worth worrying about. The Guidelines seems to me to get it just right (see link in the site's footer): >> Resist complaining about being downmodded. It never does any good, and it makes boring reading.