The thing is almost every other MMO has parsers (even if not official, but unlike Square other developers don´t ban you for using them and they are widely known) and people still don´t use or ignore them.
Back in 2008 I did some raid lead in the huge W. We parsed every raid to the deepest crap and talked to the low DPS players but in the end from 10 people maybe 1 listend and tried to really improve.
Most people just don´t care that they are bad as long as they can get stuff done. The majority stays bad, nerfs will come and at some later time they get the crap done. Ilvl improves, skill stays they same and it goes on and on with newer content.
Only thing that would help is when everyone could see the numbers of DPS/HPS/DMG taken, so the bads would knew they can´t get away with being bad because other people see what crap they do. The community in endgame content is already toxic to the limit, seeing numbers in parsers wouldn´t make it much worse.
Just my opinion. Everyone can have another.