He's conflating edgy with dark. Making dark jokes about necrophilia or serial killers or babies in microwaves will usually get an "ew gross" or rolled eyes in response. Edgy jokes aren't about disgusting or dark subjects, they're about slaying sacred cows. Everyone in the West knows what those sacred cows are, and they aren't almost pathetically earnest 30 year old dorks who look like Morel Orel. Leftists know what those sacred cows are, that's why they gleefully challenge you to say something against the prevailing libfag orthodoxy, "OH you don't like 'thugs' and 'bad neighborhoods'? What do you really mean by that huh? Huh? Go on, say it! What do you mean by 'youths' huh? Huh?!"
This is why leftists dont understand - or pretend not to understand - how racism and transphobia can be genuinely gut-laugh funny while nasally screeching "KILL REPUBLICAN CHILDREN" can't. It's why Hitler is funny but Stalin isn't. It's why everyone loved Burger King plane guy but that fat slug Frogan mocking veterans was ridiculed.
tl;dr umm it's called punching up sweaty