I think this is a core issue with reddit. They're trying to be a self-hosted platform at the same time that they're trying to be a single coherent community of "redditors" with a default, universally-applicable front page.

This leads to conflict when one person feels their identity as a "redditor" is under attack by the success of a sub that is diametrically opposed to their political or religious perspective, which leads to invasions, trolling, doxxing, harassment, and lots of other types of nastiness.