Why is he frustrated?

So this guy randomly asked me what my intentions where towards him and I didn’t know what to say and he got mad.

We don’t live in the same city and a long distance relationship seems impossible for both of us. But, he said he wants to hang out and get to know me and whenever he comes around, he’d like to see me and if I go to his city also. He wants to develop an emotional thing even if a relationship is impossible.

To me, it sounded like he just wanted someone to be physical with and I’m not down for that.

When I told him “Do you only want a physical relationship?” He said “No that’s not what I said” And got frustrated.

I even said that if he would be open to opportunities, I would too an he got more irritated.

The next day, I told him I wanted to be friends but he didn’t answer. I don’t understand why he’s so frustrated when I’m the one who kinda got turned down (I wanted something more than friendship even though I knew a relationship wouldn’t be impossible and I didn’t know what to call what I wanted).

What do you guys think about the situation? Why do you guys think he’s mad?