what is wrong with this guy?
Probably nothing. There are alot of people who don't believe that you have to be married in order to be in a healthy, long-term/lifelong relationship. A friend of mine and her boyfriend have been together for almost thirty years, have two children and live together. They are, for all intents and purposes, married (she even calls him her husband sometimes -- which was
extremely confusing for me when I was just getting to know her and she talked about her husband AND her boyfriend
) but they just haven't made it "official" or "legal" or whatever. Subscribing to that school of thought is not wrong.
You'd think that he would want to finally take their relationship to the next level.
For some people, all marriage does is put what you're already feeling into writing, and isn't necessary. Signing a paper saying he's going to spend the rest of his life with his girlfriend isn't increasing his personal level of commitment to her, so to him perhaps there is no "next level".
he had to CONVINCE him to propose to her
Well THAT was a fantastic idea
She said if he didn't, she was going to break up with him.
That's not exactly wrong either. While I think ultimatums arer't the best way to go about things, as much as it's not wrong for him to not want to get married, it's not wrong for her to want to get married and to pursue a relationship that is heading down that path. This is probably something they should have discussed seven or eight years ago.
However, if that's what's important to his g/f, it should be important to him.
If not getting married is what's important to him , it should be important to his girlfriend.
What the other person wants should always be important, but neither of them should be expected to give up what they want to make their partner happy. If we're talking about, "I want to see this bloody, disgusting action movie." "Well I want to see this sappy, girly, coming-of-age chick movie." Okay, somebody can give in to make the other person happy. But when you're talking about getting married vs not getting married, I really wouldn't want somebody to just go "Oh fine, let's do it YOUR way
this time, but
next time I get....oh wait...."