No South park hum? But Rick and Morty is there so it's not a policy against foul-mouthed cartoons; Smiling friends is also missing but perhaps it's too unknown or too recent to be there.

Pre-AI it’s tedious to find/fix/verify the subtitles — and there are a lot of episodes of South Park. Literally the reason why it’s not there :|

If you sort the top 50 best rated episodes of all time on IMDb you would already have 90% or the quotes people search for, so I would focus on your those if you ever try to take a stab at it.