I think most relevant points have already been made in this thread, but I'll toss my opinion in:
Free distribution of creation is the core of Itch, it's community, and it's mission. Any degree of enforced categorization is an inherently slippery slope, and generally A Bad Idea™.
I generally believe Leaf is a good person with a good framework for what he does with the platform. However, every other platform of distribution, for any medium, in which "quality standards" have been introduced has fallen directly into a pipeline of censorship. The end goal is pushing queer art back to the underground. Indigenous art. Black art. Asian art. Radical art. Anti-capitalist art. The sorts of things the Nazis categorized as "degenerate art" Itch has value due to it's rejection of that pipeline.
It is dangerous to put the key piece to infiltration in play, when society at large has yet to figure out how to organize widespread and decisive antifascist action, and resist infiltration.
That all being said:
I think having tag exclusion and adding a "Joke/Meme" tag is a perfectly acceptable proposition.