It’s not defederating on the basis of political opinion. It’s defederating on the basis of extreme intolerance towards and censorship of people who have different, non-fringe opinions that aren’t even controversial in most parts of the world.

Right now, the instance hosts a lot of let’s say mainstream, non-political communities, purely because lemmy.ml was the first instance and so “popular” by default. The way the mods over there behave, it’s clear that they’re not suited to be a mainstream instance for these communities. Unfortunately due to network effect, people won’t just move.

The only way to dislodge these communities and move them to more neutral instances is if larger instances like lemmy.world start defederating lemmy.ml.