Context
I'm 26, born and since living in Barcelona, I share house with 2 other guys, lets call them Bob and John. Bob is my best friend since 7 years ago and John is a friend I knew 2 years ago from a friend in common, we have a good relationship and share a lot of tastes.
Me and my best friends are natural competitors, we met each other on a tournament of a Card game, and have been game pals since. We've competed at high level on several popular games and we really enjoy the thrill of competition. I do this on my spare time, I work 30h/week as a software developer.
The other flatmate is more of a casual player, who plays just for fun. He also has less time to play games since he got his last job which has a really heavy schedule.
Lately, after a break from competing in the last card game we were focused on, we decided to start training hard again and try to win tournaments and get good results. Therefore we spend more time practicing and playing in those tournaments.
The problem
This creates situations where Bob and I spend whole afternoons of the weekend playing long tournaments, or just spending tons of hours playing during the week if we have an important tournament coming up.
John sometimes brings up that Bob and I waste too much time on that and instead - as really smart people - we should be investing our time in other more productive things.
We've had a few discussions about this. I try to explain to him that it isn't the same playing a game for fun as playing to compete among the best players in Europe/the world. We just don't get the same satisfaction if you cut the number of hours you invest because you usually see your performance decreasing as well, and honestly that's a feeling I don't like. When I compete at something, I like to do my best among the parameters I can (I won't quit my job to have more time to compete since my developer career is a safe path and well paid).
Conversations usually go like this :
John: But don't you see that with that brain of yours if instead of playing you were using all that time to study or doing your own projects or business you could do whatever you want?!
Me: I know. it's just a matter of preference. I enjoy competing in games; I've been doing it since I was 14 years old and I really enjoy it. I don't feel like giving it up for an improvement over my financial life, which you know, is perfectly okay.
John: Yeah, but think how much could you make and all the interesting things you could investigate if you used that time productively like in this Machine Learning book you bought recently.
ME: Well, I'm interested in the subject and I'll be studying it and trying to learn and see if I can make a jump to it in the next years but I won't give up the thing I enjoy the most in my life.
He's usually the one who brings up the topic and I like to discuss quietly about things. But he just doesn't seem to understand that our perception of competing in games is really different from just playing for fun.
The only solution I can see is trying to compare it with something he really cares about like music (he plays guitar and he's been doing it for 14 years, so he's pretty good at it).
Clarifications (may be adding new ones if I see it necessary)
During 2 years of college I had addiction to one of the games I was competing in, which ruined my college years and I sabotaged myself from finishing it. I didn't realize this for a while but when I did, after working on it, I quit playing for some time and tried to learn from my experience to avoid that happening again. Now I invest a little less hours (they're still a lot), but it's just when I feel like it. For some days I just don't play at all since I don't feel like it. And therefore I don't think I have a gaming addiction anymore, since the way I mentally approach it and how it affects on me are really different.
I've told him a hundred times I understand completely his concerns about our future, but the things is even if I follow my current path, I have a quite successful path, Bob isn't in the same situation so I understand his concerns about him and I've spoken with him about this issue, so I don't see why is he so bothered with me, just because I could "aim higher". But yeah, I don't see any of his attempts as attacks but rather trying to help us.
Bob and I talk about the game a good amount of time but we also discuss tons of topics (politics, psychology, philosophy,etc) so it's not like we're always and exclusively talking about that.
Question:
How can I better explain how Bob and I feel about this so that he will accept our point of view or, at the least, get him to stop trying to make us feel guilty for playing them so much?