Asexual

As a guy, lots of guys get like, 2-5 close friends and they are content with that. They don't have time to spend with more than that, why bother with more? Not everyone needs dozens of "friends"

A girlfriend/sexual partner is different. You can make an exception for a sexual partner, they're ideally going to be a friend as well, so you want to be friendly and make sure their interests are somewhat compatible. Generally speaking that bar is a fair bit lower for sexual partners.

But once they tell you it's not going to happen, they're just another potential acquaintance you aren't going to have time for. Being a "normal person" is keeping your friend circle tight and high-quality. Sounds like you were compatible enough to be a sexual partner, but not enough to be an actual close friend, so once partner was off the table that was that.

The vast majority of people aren't asexual. Better to be honest and leave than be in a relationship you're uncomfortable with

If they are looking for a sexual relationship then they are doing you a favor by leaving you alone. Would you rather they stick around and try to pressure you into sex?

It bothers me that most of the replies are trying to argue with you. It sucks to not be able to just be friendly with guys. Even if it's an ace-but-not-aro thing, it's understandable but still frustrating.

I imagine these are guys that you've encountered in the wild. It'd be really funny if you were on a dating app and simultaneously making this post.

As a dude, hyper sexual dudes suck and make us all look worse, I blame society somewhat for either literally promoting it or at the very least looking past it.