Vote up is the thanks gesture in SO. High-traffic forums moderate "thanks" messages because it increases information density, making the content easier to digest. Imagine an SO comment section with 300 thanks messages and you're looking for that one comment with relevant information.
No one's feelings are hurt, it just comes off as sounding like a dick. Just like the expression 'hurt your feelings'. (Nothing personal though, I'm sure you're swell in real life.)
I am not a native English speaker, first of all. My point is that SO is not a representative example of general internet culture, given its rules and gamified aspect(s).
I agree. I think you misread what I wrote. If we are talking specifically about SO, just realize that it is a gamified forum where comments like ”thanks” is specifically discouraged. On most places it’s not.
I don't think "gamified forum" makes things all that different. It's fine to say "I think saying thanks is redundant", it's quite another to go around and removing "thanks" from questions because it's "redundant chatter". That's just ... weird.