If you have a 'must have' device for your desktop environment that's bluetooth, then yes, it makes OpenBSD unviable for you; but OpenBSD isn't viable for every use case.
Yes, and desktop, especially laptop, is an example.
Yeah, it was annoying when I tried to pair my mouse- but you know… a wired mouse isn’t that big of a deal.
One thing that brings me the most displeasure about internet discourse about operating systems is this idea that they all have to do all the same things.
Thats homogeny by another name; the point of different operating systems is different trade-offs.
You've clearly had a different experience with Bluetooth, and that's good for you, and neither of our experiences is universal, but I think there are plenty of people willing to use a desktop OS without Bluetooth.
Heck, my new car only uses bluetooth to do phone pairing, then it switches to wifi to talk to phones, because that's clearly better than Bluetooth.
[1] for which there is an easy workaround in the form of class compliant usb audio cards that output to bluetooth.