See, this is something i don't get it. I understand Bruce being miserable as a young man when he's full of rage and depression because he's lost and feels incapable, but becoming Batman should be the happiest moment of Bruce's life and not a tragedy. That's the moment where everything clicks and Bruce can finally see a way out after decades of confusion and struggle. That's the moment where Bruce finally regains control of his life. Being Batman should pure power-trip for Bruce. It's the moment where he takes the fight back to the likes of Joe Chill.
And sure that's the moment where Bruce is pure self-actualized vengeance and probably at his most brutal, but still that's also the moment i feel Bruce should be at his happiest. Like a psychopath in his own sex dungeon.
Then you've the Bat-Family slowly being formed where Bruce is surrounded by people that see the world as him and are after the same things, so again i can't see Bruce being this lonely and depressed man after the appearance of Robin.
The problem is that most writers try to write Batman as a normal guy and if you're a normal man who want normal goals out of life, of course being a violent vigilante feels like a tragedy. You should want to party and get girls, maybe build a family, have a job, and so on. Not hurt your hands beating drug-addicts. But Bruce isn't a normal guy. Bruce doesn't want the same shit as everyone else. Being Batman for Bruce is what fixes him, not what destroys him. Destroyed he was before as a helpless and confused young man that didn't know what to do with his rage and sorrow.
That's what i think, anyway.