A pet peeve: I hate it when folks act like it takes so much more time to express a complaint than to whine that people are complaining. I think a problem is that positivity can become toxic and more negative than negativity. If I say "Man, the jewelry category on etsy is really crowded! They should put in an advanced search instead of gift guides!", that is going to cause a whole lot less bad feeling, even though it was technically a complaint than saying "I bet the reason you think the jewelry category is crowded is because you're a miserable person deep down. Why don't you leave if you're so unhappy? Why do you have so much free time to worry about that?" despite this somehow being 'positive'.

I guess the problem is that positivity is very fragile, compared to being realistic, because it does not have a firm foundation, so anytime anyone makes any mention of a negative, that bubble is burst. You can't sustain it, and you have to lash out as an attempt to keep that unsustainable world view. When you lash out, bad feelings occur. So that creates more negativity than being negative.