The general public don't want to confront degenerates (kids vaping on the bus, loud people, people insulting others with slurs, creeps etc).
Particularly late at night I don't feel comfortable on the bus and I'm a fairly imposing guy. If I were a young woman I don't think I'd want to get night buses at all.
There is an undertone to the whole public transport conversation that inevitably tends towards people thinking that you're bigoted (racist/classist/whatever) if you don't welcome antisocial behaviour, which anyone who actually had a poor upbringing will tell you is complete bullshit. There is no excuse for behaving like an animal in public.