That's where you are wrong. I may live on the continent of Europe, but I am not a Euro the difference is huge. Kind of like the difference between Mexico and the USA. Who are also on the same continent.
I wouldn't expect you to understand. I am a fashionable man living in the cool city of London, in England. You are American. The country that is well known for wearing Jeans 8 sizes too big and basketball jerseys.
That is all.
I also think jokerman nailed the point.
You live in a country known for chavs. I think you'll lose that argument LOL. But that's not what it's about. What I tried to convey to you is that the instant reaction you get when you see someone with over ear headphones on the metro does not translate to the States. That's why I said "You Euros". I can't speak for everyone here, of course, but in America you'd never associate that with someone trying to "look cool" or try to look a certain lifestyle like a certain MR. "cyber-glam-punk" lol. Even the "backpacker" label that Aaron threw out is barely sticking.
If I saw you on the "tube", with any headphones, I'd probably think you're trying too hard to fit in with the youngsters because you're in your 30s and it shows. That's not a "rule", that's just the first thing that'd pop in my head. I'd expect you to be reading a book. That's what you're confusing. It's not a rule, it's just your expectations and perceptions.
Also, you need to spend more time in the States. Barely anyone is wearing throwback jerseys or oversized jeans. Most kids moved into the whole Pharrell, Kid Cudi, Kanye, Lupe, type of look. Just look at all the young rappers coming up and that's who the kids are emulating. Nobody's trying to look like Snoop Dogg - except the Euros - because they think it's how rappers dress nowadays still.