I'm not convinced that parsing is an enforceable thing if combat logs still go to a .txt file. What I do with a .txt file is my business. Especially one that is saved outside the game directory. So I'd say have at it. If they're not doing anything about harassment, then parsers are a go since it was under harassment that it wasn't allowed in the first place.

I have used Damage Dealer's DPS against them when they've accused me of being a 'bad' healer not even that long ago. I didn't need a parser for that. I merely looked at the bosses threat table. A, 2, 3, and 4. As a healer, I should be 4 (if AOEs aren't getting dumb). But there was a dungeon run where a guy died from standing in ground effects and complained that the fight took longer because I didn't Raise them. Raise cost 1500, I had 1200MP when he died (and because of the damage he took from dying).

Got them booted for being a jerk and bad DPS.