I dont like parsers either but id rather they implement one that is toggleable so i can ignore it and just report problematic people.
Its like the gun debate, guns dont cause problems, bad ppl with guns cause problems.

Im curious though how a person will recognize a difference between rotations on a parser when criticals can drastically effect your average dps but i never looked into them, dont care to. If it gets to the point i have to worry about it or i felt the community made a turn for the worst in game with them, I'm sure I'd end up quiting out of anxiety caused by it.
I really dont see a toggleable parser in game that shows only your dps as a problem though, cant see others, in fact... I would hope this would be the means to report against ppl who are using a different parser against other people, everyone should be using the in game one if developed for "self improvement".