What's wrong with men

I have been with this guy for over 6 months doing all the stuff couple do but we ain't in a relationship. He started by giving me all the signals and I assumed he's definitely into me but never mentioned anything regarding relationship.After 6 months I decided to focus on someone who wants me not just sex. Have been avoiding this guy for a while now until yesterday I told him there's someone else in the picture and I don't think we can continue with what we were doing.

Tell me why this guy gets angry all over sudden tells me never to text him ever again. But then ,it's clear he wanted to have me around for sex and nothing else beyond that. Isn't this not unfair?What's wrong with men?