There's a world where Sun did what you hoped (became a systems company) and created Joyent in-house. However, hyper-scaling means going fast and cheap before good comes along. Sun's habit was fast and good and that's an extremely difficult hurdle to overcome culturally. (By fast I mean growing a platform, not raw performance, FWIW).
Solaris 10/11, with all its technologies (zfs, zones, crossbow, dtrace, etc), was the pinnacle of UNIX that came out just when the world changed. At a company I worked at circa 2008-12 (that was a solaris shop) we essentially created a proto-docker with containers and ZFS that allowed rapid deployments and (re)building of our systems. It was a game changer for on-prem.
Solaris 10/11, with all its technologies (zfs, zones, crossbow, dtrace, etc), was the pinnacle of UNIX that came out just when the world changed. At a company I worked at circa 2008-12 (that was a solaris shop) we essentially created a proto-docker with containers and ZFS that allowed rapid deployments and (re)building of our systems. It was a game changer for on-prem.