My comment wasn't rude, judgemental or sexual.
No, it wasn't sexual and no one said it was. It was, however, sexist since you specified that you believe only women look 'horrible' with armpit hair and not that armpit hair is 'horrible' generally (therefore suggesting that you don't believe the same about armpit hair on men).
Describing a perfectly normal, natural part of the human body as such is most certainly rude, and we don't talk about people that way here. I'm surprised you don't know that.
As I said I can express my opinion.
Yes, you can. That does not necessarily mean you'll be expressing it on this forum.