No one, given how A/UX went down.
It was a mix of not buying Be, having a reverse acquisition with NeXT, Jobs taking over the reigns yet again, Sun doing a bunch of bad decisions.
Nowadays, following the spirit of old Apple, they only care the UNIX underpinnings as good enough, and that's about it.
Still, they managed to bring Unix to the masses. On a RISC platform even.
And their Unix is just fine.
UNIX had already won the server room by them with RISC.
Lets not pretend outside IIS with ASP, later ASP.NET, Active Directory, Sharepoint, SQL Server, SMB, there were any other deployment scenarios left for Windows.
Who could imagine Apple would eventually inherit Sun’s crown as the king of the RISC unix workstation?