Not everyone finds slogging through meaningless trashmobs that can't do squat except have ridiculously high HP pools fun.
Yes, scaling like that should be a players choice. I didn't like scaling in GW2, I don't like it in WoW.
Why have a leveling grind in the first place if crap scales UP to you anyway?!
Only scaling the kind FF XIV uses in dungeons and FATEs, because it makes playing with low level friends much less of a pain in the rear. Even then: it is my CHOICE whether I want to do a low level dungeon or FATE.