Boy tells me he is "not attracted to me"

Hey. I just wanted to vent online. I'm 28 and there was a boy at school who used to flirt with me and like me. We never did anything at school but then he visited me for my 21st bday party. I got drunk and we made out, and we did things but not sex. Then I asked him where things were going and he said he didn't want anything serious. And then we were planning on having some fun after we graduated but we both sort of went our different ways and he started dating someone else (I was OK with it) and we lost contact. We got back in contact recently (I'm 28 now) and began texting again. We sent eachother a few dirty pictures and then planned to meet. He rang me last week and we had a few naughty skype sessions and planned some sexual things to do. He had been fine with everything, telling me he wanted us to meet and do sexual things. Then I messaged him today asking if he wanted to come over. And he replied "I'd rather not... I've had a change of heart. Probably because I know it won't go anywhere" and I replied "I know that I thought it was just fun?" and He said "I'm not really attracted to you either. I guess I thought I was, but have now realised I'm not." I told him to delete all our messages and never contact me ever again and told him I was going to block his number. It's OK - I'm 28 and I'm an adult and obviously I'm a little hurt cos I'm a human being. But I'll get over it, it's not like I'm an insecure teenager. But why do you think he did this, and are you shocked by what he said? Do you think that is really brutal?