Then you have warg tails from the 5.1 dungeon, the shisui sets that are super revealing, the sky rat sets...plus as other people are pointing out, dresses for healers/casters etc that people often glam over.
On the technical side of things, we can really only guess at how hard these solutions would be since none of us have access to the code. Maybe it'd be super easy to add a glamour blacklist. Maybe the time and effort it would take isn't feasible for the game's budget and resources right now. Remember that time spent on this is time not spent on other features, fixes or changes. Maybe they could do it without affecting performance, maybe it would affect performance in high pop areas evne if you don't turn it on since the game still has to check when rendering characters.
We can only really guess either way without input from the dev team on the technical side of whether this is feasible.