I'm going to loudly heckle cat-callers
because they were cat-calling you?
Because they are unpleasant to look at and they make me feel unsafe
Although it's wrong of them to cat-call people, you shouldn't heckle them. You should politely tell them to leave.
There's nothing wrong with protesting against cat-calling. Then they will understand why they shouldn't do it anymore.
You're right that there's no reason to be cat-called, but instead of heckling them, what if you just started a conversation instead? Let these people know that you're a human being who should be respected, and maybe then they will stop.