I don't think you've experienced many unhinged and screaming homeless people. They are intimidating, gross, and they have nothing to lose. Telling them fuck off only escalates. And then you'll have to deal with getting the inevitable feces pie to the face.
I had to deal with something like this a week ago.
Took members of the club I advise at the college on a trip to Chinatown in Chicago.
One of them is a 19 year old girl that looks VERY young for her age. Could be easily mistaken as an 8th grader.
As we're boarding the platform for the Red Line to go back to the 35th Street stop, this dude starts harrassing her, telling her he's her father and that he has to go on this train with her. Even blocked the sensor with his hand so she couldn't scan her Ventra card and go through.
I had to intervene at that point and start telling the guy to back off. 'That can't be your daughter because she's my student and you're just some trash hanging around to prey on girls.' Said it to him just like that.
He was loud about it and insisted he was her father and I told him if he didn't back off, I was going to end up fired and in jail over what happened next.
Got everyone on the train and safely away from this dude.
I'm not even going to talk about all the potential scenarios that might have happened had he tried to kidnap her or something.
And don't say 'that wasn't gonna happen.' If if you've never had crazy in your face yelling at you, you don't know what you're talking about.
It can't be ignored, it must be dealt with. Period. Just glad I didn't have to stomp a motherfucker out that day. We were having a nice time.