It's not just the occasional DPS check. DPS makes EVERYTHING easier. Fights today take a fraction of the time they took on the round of TLP's that existed before these buffs were added. In the past, guilds didn't beat raid zones like Anguish or DPoB just by showing up with 40ish toons. Now, you can beat Lethar 2.0 just by showing up with a full raid--not a single guild has attempted it and ultimately come away unsuccessful, as far as I am aware. Quite a few guilds on Fippy/Vulak struck some brick walls along the way and never defeated all the content in these expansions, despite having the #'s for it. When your DPS is lower and raids take twice as long, now you have to execute everything else nearly flawlessly, not to mention having the appropriate gear to survive long enough on all your members. DPS smooths over all sorts of challenges and makes the road nice, flat and easy for everyone.