"Reboot to initialize" is ugly as hell and very brittle, but it's good enough for most I/O devices like keyboards or headphones. If the kernel is able to properly reinitialize the chip with all of its old association information, it might even be indistinguishable from a few hundred ms of interference. (Rebooting on errors is in fact quite common for all kinds of hardware in high-radiation environments, and is a pretty standard kernel technique for working around buggy hardware.)

Now, of course, multiple nines of uptime would be very nice to have (and open up new use-cases), but 2-3 nines is still a lot better than 0.

Fine, but you're rationalizing living with poor execution. I'm rationalizing with deep (perhaps goldplating) correctness.

I'm not "rationalizing", and neither are you.

You're arguing that it's not enough to make a correct implementation, but that it's also important to break compatibility with incorrect implementations.

I'm arguing that a better implementation that is compatible with current protocols is strictly better than a better implementation that is not Bluetooth-compatible.

If you make a piece of hardware that is good (e.g. doesn't randomly crash and need to be rebooted by the kernel), why is it a bad thing for it to try to connect to some flaky BT headset?