Role-playing is not playing dress-up. It's about stats, not about looks.
You CAN'T play Gandalf (or some specific character), unless the game specifically casts you as Gandalf (that specific character). If you're playing it in "your head", then keep it there. If in your mind some random character you created is Gandalf then you can just imagine he's wearing his clothes as well.
Or, if you think that the character you created should wear THIS but definitely not THAT, RPGs are not for you and you're the cause of the decline.
Because, in real life someone actually sees you. In a computer game, nobody does. And if you think the people in the game care what you wear, you have serious troubles. Similarly, if you only play games to look cool and make screenshots to show to others, then again, please leave RPGs alone and play some dress-up game or something.
RPGs are not about satisfying every little disturbed fantasy of everybody out there. Why can't people just leave them alone and go play Bioware dating-sims/dress-up games?
RPG = stats.
RPG =/= hats