Exactly. Why would you trade something that doesn't require power, has the most reliable, secure, and lossless transmission channel known, and is "configured" by plugging in hardware for something that requires power, has a less reliable transmission channel that can be easily snooped or forged, has to be configured in software? I literally don't understand why anyone would ever choose the latter.
I don't: wireless headphones seem strictly worse in every way than wired. They require batteries and charging; they introduce lag; they are expensive; they are easier to lose; they don't have a convenient cable to hang on to.
I am completely and totally flabbergasted by their popularity. It's as though millions of people were turning their noses up at fine, free homemade French food and paying for McDonald's instead.
Although...different use-cases there, for me. I've got a dozen audio sources, either connected to speakers (the TVs) or within a couple feet of me when I'm using it (phone, media player, tablet, laptop). So, a bunch of sources, a couple of which I might be listening to at once. All either in short enough distance for cords, or loud enough that it's moot.
Wifi: The internet comes from one (inconvenient) place in the home that I can't choose. I've got a couple of powerline ethernet adapters, but I've also got a lot of devices that handle wifi, but not ethernet. The choice is between using wifi or skipping the network connection. It's great as a last- (or only)-resort connection option, and it's usually sufficient, but then my uses for it are usually pretty tame anyhow.
Bluetooth was originally encrypted, but gained the option of non-encrypted channels with version 1.1.
On top of that Bluetooth use frequency hopping.
Until recently there was no real hardware for scanning/sniffing Bluetooth traffic, at least not anything easily available compared to a wifi card in promiscuous mode.
As a matter of fact, my desktop & my laptop are both wired, and I hate how flaky WiFi is on my phone & tablet. Just moving to different rooms in my (small house) does horrible things to my network connexion speed — but Ethernet keeps on chugging along.
So you don't believe that somebody would like to be able to use wireless headphones?