> I certainly think "I'm routinely regarded as an a-hole because I act like one" to be much more plausible than "I'm routinely regarded as an a-hole because this giant social network has a metaphorical auto-immune disease that results in me experiencing this routinely."

Especially when others participate in that same social network and don't experience that same problem.

The one benefit I could give this person is that they are seeking out subs that have a high likelihood of being ran by highly political moderators and are extrapolating that to the whole of reddit. The same could be true for what kinds of discussions they find themselves participating in. If they are attracted to highly political communities and controversial discussions, they would have a higher likelihood of running into such issues.