There is a saying that "scarcity increases value". By making something rare, or in this case, harder to get, the value of said item increases. This is the approach Bungie is taking toward their transmog system. And honestly, it's a more believable, and smarter take. If you want to give your house a makeover, for example, you can't just change the color of your walls willy-nilly, you have to go out, purchase the paint and primer as well as some sandblocks. You have to sand down the old coating, prime it, paint it, then sand it again. It takes time, it's complicated, but the end product is well worth the effort. Or you could hire professionals to do it for you (the microtransaction counterpart in my analogy). Sure, it would be easier if Bungie just let you change your armor's appearance on a whim, but that would cheapen the act. Because you could choose what you look like in any given moment, any customization would be a fleeting experience. But put the effort into choosing your new look, you are bound to appreciate it more, something the youth these days need to learn how to do.