This reminds of an almost off topic story. A friend of mine here in the US once hosted an exchange student from Russia. On the way home from the airport, he stopped at the grocery store, so he could stock the house with food. The kid that was visiting was absolutely amazed at the number of choices that were available. For example, in the US there are about 100 different varieties of potato chips (or "crisps"), whereas Russia evidently isn't like that. "How do you ever decide what to buy?"
I think most people choose a favorite brand or a few brands and stick with that many products. They don't add another brand to the list unless someone recommends it or it catches their eye for some reason. I think headphones, and electronics in general, are the same way.
Plus, if there wasn't so many different products, what would we have to talk about?
