I hate to admit it, but I'm more a function over form guy when it comes to hotels.
A weak shower, lack of power outlets, weak/noisy AC, lack of workspace, curtains which don't block out light, and many other things will be noticed & remembered by me long after the initial impression of decor.
I don't mind tasteful theming. Some of Disney's properties, especially their lower end, are rather dreadful, to the point that there aren't many brands which would allow them to be brought into their chains. Outdoor hallways & window ACs? That's so 1960s, and not in a good, fun retro way.
Actually, I do want SOME theming relating to the area in a room. I hate when I get to a hotel in a foreign destination and the room could have easily been out of a hotel in Kansas. Worse is when you wake up and have to look at your phone or the hotel phone to figure out which country you're in. Even a few photos / paintings of the area go a long way to personalizing the room to the locale.