I don't mind that things get reused in a general sense, but it is frustrating when the ratio of reused assets to new ones can be seen increasing over time. Like everyone said, pretty much every other MMO, every other RPG, every other video game creates the illusion of more variety with palette swaps and different textures, and it's better than not using them and having the exact same things repeated across the world (looking at you, PS2 era FFXI). But it also isn't great when you can clearly see less new stuff in the latest expansion than the ones that came before - notably the distribution of gear sets in the dungeons in 6.0 - we know they could make more new things because they have before, and the game seems to be more popular than ever.