This is the second post I've seen about this and I'm genuinely not sure why it matters. :s As people pointed out in the other post: maybe she had a shit personality? Or a personality that wasn't compatible with his. Maybe he is minorly asexual or such. Maybe he just loves video games and it's his passion and he wants to dedicate his time to that. Maybe he didn't have enough time to spend with her as a result, and couldn't give her a relationship he felt she'd deserve. Or maybe she was miserable about the whole thing. I don't really see why they're treating it like karma that he ended a relationship partially for the love of a hobby that he subsequently didn't manage to be the absolute best in the world at. If someone broke up with someone to dedicate their time to learning to play the piano, perhaps professionally, Nobody would call them out for not rising up to the ranks of Beethoven or Mozart
Another thing to remember is he's probably much better at COD than any of the people laughing at him are at anything. I forget who said it but there is a quote saying something along the lines of "you need 10000 hours in anything to truely become a master at it." This guy no doubt has at least that in COD while most of the people laughing at him probably put the minimal amount of effort into their work seeing as that's the norm.
He’s a professional gamer on a contract so gaming is his primary source of income and career. The pots for winning these competitions can put tens if not hundreds of thousands of dollars in the winners’ pockets. In an interview, he said that the breakup was amicable, that she also wanted to focus on her job, and that they’re still friendly. As @xvarnah said, this wouldn’t be an issue if he broke up with her to focus on a more ‘noble’ career.
That looks like the domicile of a successful "pro-gamer".