As far as I can tell from on the usage of based I've seen, it means cringe/unpleasant/racist (depending on context).
Similarly, “based” is used to mean the opposite of “cringe”. It just so happens that most “based” content is what others might call cringe; the video I posted above is satire of exactly this. However, it doesn’t change the meaning of the word, and in fact the joke falls apart if you redefine it this way.
Words have multiple meanings. Clearly based is one of them.
Again, you need to separate your feelings about the things being described as “based” with the meaning intended by the people using the word. If I hate hippies and think anything they call “groovy” is really ugly and uncool, that doesn’t mean I get to just declare that “groovy means ugly and uncool”. That’s what you’re doing.