So in your opinion, the only interpretation as to why this is funny is because gay man bad?

Not the OVERWHELMING, BLINDING, BURNING hypocrisy of the situation? That doesn't factor into it?

If that's the only explanation you can come up with, maybe you have some homophobia yourself.

Your opinion is gay

As a queer person who started their antifa activity over twenty years ago defending LGBTQ marches baseball bat in hand I find this post fucken hillarious.

This dosnt even register at such levels for me but around my parts a lot of gay humour is based around use and abuse of slur terms, also to take them back, as was done with "gay" or "queer". Hardly anyone but closeted selfhating guys and the instagram raised youth would have a problem with implying a right wing politician is gay. Preferably in their "gayest" voice to a bunch of terriefied normies. It also might be true for a key figure of our national politics, but that's another story.

Because most of the staunchest homophobes are gay man with very serious problems with it, followed by weak minded guys trying to be more manly it makes sense to hit that. Addressing and poking fun at that from our, known to be overly "correct" side puts them out of balance, causes rifts, suspicion and rises pressure in their own groups leading to more conflicts and divisions, therby limiting their reach. In my country we had stirred such gossip on purpouse and involuntarily outed some of far right leaders, so now the suspicion persists in their ranks. Their weapon was turned against them.
Even if you have more issues with such aproach then people who'd been oppressed most their life: it is in fact a war comrade, and you better get around to what that actually means. No one gets out of one both morally impeccable and alive.