Because they went about it the wrong way. They made their own distro, their own office suite etc. I believe they would have been successful, if they just used already existing stuff, instead of reinventing the wheel and taking on all the development obligations.
What Schleswig-Holstein is doing, is using en established distro, with established office suite and established cloud solution. They only maintain the servers and maybe patch-fix issues, which they could then upstream.
Bluetooth is not secure. OP is not looking for security, just bluetooth audio.