Why do people shame bottoms so much?

I am a 26 year old gay guy. I was hanging out with some new gay friends the other day and one of them is a friend with benefits. So they all started guessing who the top and bottom was and they called me out for being the bottom. I didn’t want them to know either way but my friend told them I was a bottom. And then he was like he’s a good little bitch too. They all started laughing and just kept going. They just kept making jokes about me being a bottom. One of the guys was like does it bother you that we all view you as a woman now. I defended myself and they were like men don’t get down on their knees and take cocks up their ass. They seriously would not stop and I got pretty upset. Then they mocked me for getting upset and started saying things like of course now the bitch is gonna cry. They even started to physical mess with me and joke that I would probably take all their dicks if they gave me the chance. I have a lot of other problems in my life (including a major drug problem right now) and I need support in my life, no ridicule. I started to find new friends recently because I felt like all my old friends were judging me (especially for my drug problem) and they were becoming distant. Why are people so mean and why do bottoms get messed with so much? We are all gay and some guys have to be the bottoms. You figure tops like that would appreciate bottoms more. I wanted/want to get back at them somehow but I’m not the most clever person and I couldn’t think of anything to say to them. And the things I did say to them they just responded by saying you take it up the ass. No one here respects you. What kind of friends are these people? Not one of them has apologized and they’ve even kept it going on a group text and 1 on 1 towards me when I’ve interacted with some of them alone. I told my fwb how messed up it was the other day and all he had to say was you know you liked all those people knowing I fuck you. Ughhhh what’s wrong with the gay community?