I agree with this man. I have seen this too and sometimes after I've already upvoted someone's comment, I will see that they haven't upvoted my post and it's kind of weird to me lol they spend the time to write a nice post but don't upvote it. I guess the only thing I can think of is that they wanted to give their 2 cents (not literally) but maybe didn't feel like they could give you enough $ as an upvote? I don't know, that actually sounds like a cop-out. Good post man, like the discussion around etiquette here; raises awareness.