For literally years now, people have been asking for Bluetooth functionality in Android which is not there. One notable example is audio-to-headset, to permit listening to music on a headset device which does not support the bluetooth stereo audio profile. My pet issue is pinless trust, which is needed for devices like the Sony BD Remote and many Logitech mice which use no pin code. This has been a known issue at least since Gingerbread. Why is it still a problem?
This problem, of course, has long been reported to google; a quick search turned up issues #23527, #26041 #52529 (where I added my own complaints.) And there is a workaround in the form of the Bluetooth Pairing app. Just one problem: Google broke it in Android 4.2.2, when they re-engineered the bluetooth stack. It works fine on at least Android 2.3.2 through 4.1.1, but it hangs on 4.2.2 and then eventually does nothing. I have no 4.3 devices, so I don't know if the problem persists there.
It's hard to take Google seriously when they claim they care about the user experience if they don't even care about supporting basic bluetooth functionality.