The condition, and what it implies about you, are often far more insulting than the compliment is complimentary. Even if you have crossed a low bar, like if you are legitimately a novice at something, it's pretty crass pointing that out to you within the compliment itself. "You're pretty good for a 3-year-old" only flies because 3-year-olds are too dumb to know they're being insulted.
Daniela Solomon/Moment/Getty Image
"Thanks a lot, dad! Hey, I don't care what mom says about you; you're all right."
And if you're not a novice, if what you've done is legitimately impressive, having someone attach a fucking condition to it, implying you crossed a lower bar than you did, is downright offensive. Telling someone she's pretty good for a girl is a great way to have a pretty-good-for-a-girl punch land in your throat.