Nowadays the standards for Linux support are much higher. This isn't the 1990s anymore. Releasing a half-assed support that will be obsolete in six months is pretty much useless.
Also, the fact that the drivers have not been upstreamed tells me they're most likely sub-par in terms of code quality and possibly stability.
What's the point of buying hardware whose softwares support is already deteriorating ?
Go all in or go home, qualcomm.