TL;DR;

It's weird to be upset at people for having personal boundaries/morals/ethics.

Using "purity test" like a pejorative, because using a more accurate term makes your argument sound bad, is a bad faith approach.

You say "purity tests" like it's some sovcit term imbued with magical powers, like DEI or woke.

Headcanon replace it with "personal ethics and morals" and you might see how some of those arguments are really just people having boundaries.

An example of what i mean.

This is the biggest issue with niche communities: purity tests.

They can’t unite under one goal and have productive discussions. They are more focused on being correct (their interpretation of correct) and shutting out the incorrect than getting closer to a goal. Sometimes incorrect can be as little as choosing the wrong utility and other times it can be much bigger but they all spark the same amount of ire.

vs

This is the biggest issue with niche communities: personal ethics and morals.

They can’t unite under one goal and have productive discussions. They are more focused on being correct (their interpretation of correct) and shutting out the incorrect than getting closer to a goal. Sometimes incorrect can be as little as choosing the wrong utility and other times it can be much bigger but they all spark the same amount of ire.

See how the rest of that statement sounds without the bad faith, magic-word interpretation ?

I'm not expecting any good faith arguments in response, so don't worry, this was a just-in-case kind of thing.