I literally don't understand why people automatically assume you hate them or feel insulted when you ignore them. I mean, i used to feel like that too, but then i pretty much understood that people's actions and motives aren't always that black and white. There can be a lot of reasons why someone acts the way they do. Moreover, if i don't like someone and am pretty sure they don't like me either, why would i want to interact with them? If my presence makes them uncomfortable, wouldn't that make them even more uncomfortable? (and create a social expectation to always be awkwardly smiley to each other?)
I guess i'd just like for people to look inside themselves a little bit before assuming they know people. But if they want to believe that someone hates them so much without any real reason,whatever!