Well I can't speak for anyone but myself. But I know with me, I'll never quit poker. It's in my blood. I may go 6 months or a year without playing, but there will never be a day where I wake up and go "the last poker session I had will be the last game I ever play" it's just not going to happen.
That being said I have been a notorious fish, losing somewhere between 30k and 50k over the course of the last 7 or 8 years of playing poker. (Much of this can be explained by a complete disregard for
bankroll management, as well as very bad play. I believe I'm just now getting to the point of being a decent pkayer)
I've only ever managed to work up a proper bankroll once. Sure I've ran $100 or $200 up to $700 or $800 or even $1000 or $1200 before (doing that right now actually, turned $115 into just over $700 in 3 days, again with no BRM) but only once did I actually build what would be a proper bankroll.
It was back in late 2010/early 2011, I turned $100 or $200 into just over $4400 over the course of 2 or 3 weeks grinding 1/2Nl. I thought I had turned a corner, and I'd never go broke again. Oh how wrong I was. After peaking at $4400 I feel back a bit and coasted for a week or so, before watching my bankroll start dripping away day after day. Finally, after 3 or so weeks of losing I found myself down to my last $1200, I should have moved down in stakes, in fact I should have moved down it stakes much esrlier, but I didn't. It only took me 3 hours to lose that last $1200.
I've vowed to myself if I could ever build a bankroll like they again I would practice BRM and never let that happen again. So far that's never happened, but in really determined for this time to be the time.
I don't think you should ever quit playing poker unless you just don't love the game anymore.