...because they are absolutely terrible quality.
This is the second pair of AirDrives headphones I've bought (the first pair were normal, rather than sport). I prefer the design of these to my first pair, but in general I was very pleased with each initially. I hate having things in my ears, but I also prefer to have two separate ear pieces as opposed to a pair that goes over my head or behind my neck. Oh, and I like having volume control and a mic inline. Which really doesn't leave me with many options, but these fit all of those requirements.
Except they last about a month before they start to fall apart. The cord frays, one ear piece will start going in and out, and eventually they'll stop working altogether. Which I could handle if they were really cheap, but they aren't. I'd pay 2-3 times as much for headphones of these exact specs/design if I could be guaranteed to get a few years of use out of them, but I can't afford to buy $30 headphones once a month, and I can't bring myself to continue supporting such lousy manufacturing, even if the product design is clever.
So please, airdrives, would you make some headphones that don't fall apart? I'd be so grateful.