Political humor

That's kind of missing the point. You can object to someone's actions even if they say their actions are for a righteous cause. Say someone says they are anti-PETA, and the response is that if they object to the ethical treatment of animals, that must mean they support animal abuse. It's a disingenuous argument because what the first person meant was possibly not that they object to the literal meaning of the name of the organization, but instead that they have an issue with things people calling themselves members have been doing and saying, and it's being deliberately misinterpreted.

Now maybe that actually was what they meant, or they meant both; there are people who support animal abuse. Maybe they are wrong to be anti-PETA, for reasons other than the name. But that type of argument is still a dishonest smear aimed at unconditionally rejecting all possible criticism.