DPS meters and why they're necessary

[LetBloodline]

You're asking for valid proof of those who are against it so let me ask u then for more than 1 example of where a end user parser (or player) was needed or was crucial to improve PvE of a mmo game, not beta/alpha games we are talking about a end product here.

Every game where you need to test rotation, in wich you need to test different items with different stats, in wich player want to give their best and be able to check how they are doing. Pretty much every MMO out there