Most interactions in a city are neutral: you can walk past a thousand people in a subway without conceiving of it as an interaction, you just ignore them and they ignore you. In a way you couldn't do it you met in a wilderness.

That is a bold statement I do not understand why you think it is true.

I am trying to understand how your concept about a common hate connects to cities. You are comparing leisure time "the wilderness" to work time "the big city". A city lets you choose your interactions, and it forces you to see things that are not only the hate in your bubble. The possibility to have an interaction that changes your world view is greater in an integrated city.

Hate can grow even if we all sit in a corner of the woods on the internet, or if we listen to the same radio host.

There are too many cultural aspects in your view of the city, I do not know where you come from here. FWIW I have lived in mega cities, and also for years outside of cities in some of the least populated spaces in the "developed world". My experience do not reflect yours at all.