Why do so many trans men/masc people get offended if people say they “look cis”?

First off, I want to say that this is not everybody. I’ve just noticed that it’s becoming more and more common.

I’ve noticed now that a lot of people get offended if someone says they “look cis” or that the person “would never have known they were trans.” Personally, I think it’s a compliment, because I transitioned to become as masculine/cis looking as possible (personally). The other day someone said that they’d never have thought I was trans and another person said “that’s not the compliment you think it is.” and I was so confused. I see it all the time on Instagram and stuff too. I’m legitimately confused. I thought the point of transitioning was to be able to be recognised as another gender, but apparently it’s not? Someone please explain.

Tl;dr: the title

EDIT: I just want to state that the people who have said this to me, or others I know, are our friends and relatives who know us well. It’s not just random people who’ve found out we’re trans.