You are not thinking, you are merely being logical.
It's true. I see them sometimes standing quietly in the corners of pubs or gigs, fascinated by everything and desperately trying to blend in. But they always slip up and get their outfits just a few years wrong. They’re like American tourists who heard that everyone in Istanbul wears a fez or everyone in Paris wears a beret.
The cool thing is they’re from the future so they have the confidence to pull it off. The even cooler thing is that they look so amazing that kids start copying them, and snap, they just started a fashion craze. Name almost any fashion style over the last few years and I guarantee it was started by a time traveller fucking up trying to blend in. Wayfarers, plaid shirts, fanny packs, fluro, geek glasses, bow ties.. The list goes on and on.
Sometimes time travellers get their outfits just a little too wrong for it to catch on. Maybe they didn't read their guide book or something. Like the guy I saw wearing star trek glasses and a full length leather cape a few years ago in London. Or this girl trekking her way through the streets of New York.