Unless it's about scam red-pillers who don't really know what they are talking about gives false expectations and charge a lot for courses and books, I can't see what's bad about redpill. So I would be appreciative if someone could give me their perspective as to why redpill is bad.

I suspect there are some females here, annoyed that they didn't get to keep a really attractive man that made the impression he would be yours; you should have realized he's over your league. Or just angry at men in general, which is also not a good argument against redpill.