Why are wireless headphones so rare?


Almost everyone I see using a portable music device is using headphones tethered to the device by a wire connection. I use them too, but the wire is a pain in the butt to say the least and constantly gets tangled. This must happen to others as well and there are wireless headphones out there that aren't outrageously expensive and get at least decent reviews soundwise (I just checked this out). I'm probably going this route but just wondering why the wireless 'phones seem so rare out there? Why do people keep putting up with the hassle of wires? Is it just a lack of knowledge about wireless headphones? Anybody have experience using these products? Thanks for thoughts.
soix
Bose just came out with a wireless Bluetooth headphone, the AE2w that has some nice features. Very lightweight and comfortable they will pair with any Bluetooth enabled device.
I had to walk through two feet of snow to get to school, and had to cut through a unplowed cemetery to boot. To make it worse, I had to do this wearing Levi's, carrying my books and smoking a Marlboro with one hand and a ghetto blaster with twelve D batteries in the other. Then I had to go to ski club after school and do it all over again. Luckily the Walkman had just been invented and I could crank cassettes on the chairlift through my $200 Walkman which cost more than my skis and boots combined. Doesn't anyone roller skate with a ghetto blaster on their shoulder anymore? I don't have a problem with wires. I notice them but they don't bother me because they've always been there.