Am I being unreasonable for not wanting to see family due to differences in political views?

Background context: I’m left wing, the rest of my family are right wing. Some more than others. I have had many political arguments with my parents, now I just try to avoid the subject as much possible. I do not live close to my family, and all of my family members are spread around the country (UK) so we don’t all get together regularly anyway.

I was talking to my mum on the phone earlier, and at some point in the convo, the recent family gathering we had was brought up (took place a few months ago). I do have regular contact with my parents and my nan, but have barely any contact with my aunt and cousins. We’re not close and never have been. But my nan guilt tripped us into having a big gathering for the first time in many, many years. We did it to keep her happy - it was okay, a bit awkward but not terrible.

Since that gathering, I have now found out that my male cousin (who is in his late 30s) is a big Andrew Tate supporter. I also found out he has been pretty shitty to his girlfriend (they have just split up), apparently telling her things like “don’t eat that, you’ll get fat”, or “you’re so stupid” (he says this in front of people btw). Since they broke up, he also made a comment to my nan about how he “didn’t even find her attractive anyway” and “I think she’s a bit psycho, not surprising really when you look at her family. I mean her sister’s a lesbian!”. I was glad to hear my nan gave him a good telling off.

I’ve also found out that my female cousin (sister to the Andrew Tate supporter) is a Tommy Robinson supporter, and has gone to his marches before. Also found out that her partner was arrested many years ago for trashing a Mosque with his mates.

Going back to the phone call with my mum, she mentions something about the family getting together again at some point, and I said I don’t want to be around my cousins. I pretty much said “sorry if this sounds petty or horrible, but I don’t want to see them. I don’t like their views, and if they were anyone else, like a work colleague, I would have nothing to do with them. Just because they’re family, it means nothing to me. It’s not like we’ve ever been close anyway.” to which my mum scoffed a bit, and said “I don’t think it’s right to not speak to people because they have different political views to you” and I replied “no, this is different. It’s more than just political views, these are extreme and to me it says a lot about their morals”.

So am I being unreasonable? The thing is, my cousins make no effort to have contact with me, and vice versa. The family gathering was the first time I had even seen my male cousin in 8 years, and my female cousin in 4 years. We’re not close anyway, so I don’t think it’s a big deal that I don’t want to be around them.