I may be one of the only people who dislikes transmog. I think it actually took a lot out of the game.
I remember when I was around level 20-30 and there was this level 60 warrior on a mount with some freakin cool gear. It made me want to go to these raids and become a cool kid myself.
If you wanted to roleplay, you could still carry a non-combat set to dick around in. That being said, I do understand why most people like it. I just think it's overall bad for the game.