so exes that respond still might hit it one day

My buddy and I had this talk last night. He says nothing's wrong with texting females even when they turn you down because you get in their head and make them think about you so you just might get lucky one day. He said this more true with an ex. If she responds then you still have chance for anything you might want from her and you just have to be persistent and not take anything personal. He was saying that to counter me saying you just look desperate and need to move on. He said only if she not responding to you. Even a simple reply that says hi is good even if she has a man.
I don't know what do you all think?

By the time an ex hits me up, I've already moved on. Under my one strike rule, I won't give her another chance. She's likely trying to get another beta orbiter anyway.

There's always a reason for a breakup, and it's typically loss of interest or a better person entered the picture, or the ex came back. AFAIC, I'm moving forward. Backpedaling does no good. It's better to go after a new woman who has high interest.

see that's funny to me how we all say women don't take they exes serious but we're all worried about her going back to the ex when they're on contact with them

There was a reason you broke up. Is now the reason permanently removed? The only instance I could think of is the guy lives at home and parents hate her, she can't take it, she dumps him. Then he moves out, she comes back. That's pretty much the only instance I find it acceptable to get back together. If she got a crush on someone, then realized the guy was way worse than now ex and she comes back crying, then hell no.