Okay, good for them. It doesn't bother me if people care or not. Doesn't change that I still want to choose how my characters look for both myself and to other players, and the option to disable other people's glamours invalidates my choice for how I want to present my characters. I'm not fond of some of the more ridiculous glamours some people come up with, but I'm not so thin skinned about it that I'm unable to accept that it's just part of the game and look past it. In the grand scheme, it's really not that big of a deal and doesn't upset me if someone wants to dress up their Roe in nothing but a chocobo mask and thong, for example. If anything, seeing someone wearing an over the top ridiculous glam just gives me some insight about the player behind the character and whether or not I'd want to interact with them.
I don't do Savage or Ultimate content, but the difference is that I don't whine and moan about it existing because it doesn't personally cater to my personal preferences. I fully accept that it's not something I enjoy spending my time doing in game, and I instead focus on the things in game that I do enjoy. Just the same, not everyone's personal glam is going to be my cup of tea, but I'm not going to whine about it if they choose to make their character look ridiculous.
If you're going to pull out the 'but client mods' argument, then let me instead ask why haven't you just modded your client to swap out ridiculous items with bland items? If you consider it a valid solution and the issue really bothers you so much, then there you go that's your solution. And no, I'm not advocating for breaking the ToS, just pointing out how moot your argument is.
But for the record, I dislike that other players can and do use clothing swap mods which can break the aesthetic look I'm trying to present for my characters. Also, trying to reframe my personal preference as a 'fear' is a disingenuous attempt to invalidate my position by trying to portray it as irrational.