That's not it, meters have been since Vanilla
Yes, and I have spoken to many a Vanilla player that says the parsers made the game worse for many.

and the game continued to grow all the way into Wrath.
That spawned Gearscore, to this day one of the most reviled systems ever introduced. Bad choice.

If anything, the game is losing people due to game design and the dumb ideas that come from the lead designers
Many I have spoken to who quit WOW cite multiple instances of vile, almost obscene language enabled by parser use.

SE makes the game with DPS checks in mind which means that it requires you to optimize to some degree. Does that not foster environment then? By your logic they should get rid of savage, extreme trials, and ultimate.
Yes they do. And as has been stated, those encounters can and HAVE been cleared WITHOUT dps meters. The vast majority of console players dont use dps meters...and they have done it all incl Ultimate...so by reflection, your argument falls flat.