I dont have a bluetooth headset and I dont know anyone that has a bluetooth headset. Not really a problem.
Quite a few people own bluetooth headsets and they are pretty great these days. It would be a nice feature to be able to use BT headsets with the console - especially in docked mode. With no jack on the controllers, headsets are going to be essentially non-usable with the Switch in dockmode unless your stereo or tv can push out a BT signal..