A character such as Thancred is designed in a way that is objectively far less jarring than a character clad in a frog or pig suit. The development team are even on record stating that content such as Hildibrand is locked away in its own little bubble because such things are not everybody's cup of tea. As such, the request to block out such things isn't really that unreasonable.

Let's not forget, World of Warcraft started to rapidly lose subscriptions and relevance right around the same time that it chose to take itself much less seriously than before and replaced subtle jokes and references with entire questing zones based around the plot of certain movies.

I won't speak for anybody else, but I enjoyed WoW right up until that happened in Cataclysm. I'd hate to see FFXIV take the same route - and so far it hasn't, though the ability to block out certain glamours would be an excellent compromise.