Why do ppl insult you when you reject them ?

There's thiq guy who claims to love me very much, and it did seem like it. Thing is I was not feeling comfortable, and we were not compatible, nothing in common, literally nothing. So i refused.
at first he was okay, he said I respext your choice. Although it took a week of I don't want this for him to get it because he was acting all dramatic.
Then few days later. I received a bunch of insults by message. So after some days I became worthless, and he doesn't even know why he liked me, and i wasnt special anyways. Okay this is meh whatever.
but again some days later, I became a man eater b#tch, evil, mean and unsensitive, cold and a devil in human form.
If anything he's showing I did well in rejecting him.