I'll have a soft spot for Solaris, but the writing was on the wall long before this. Solaris was stagnating even before Oracle bought Sun. It was obvious that Sun lacked the resources to maintain their compiler suite and operating as well as actively research new technologies. It was sad to watch, but such is life. Solaris was probably the most usable desktop UNIX before OSX took that crown away. Solaris tried to add much-needed things to UNIX like role-based administration, light-weight virtualisation (zones/containers), non-intrusive profiling/caching (dtrace), advanced storage pools (ZFS), and heaps of other cool stuff. Sun SPARC hardware always had cool high-availability features like being able to disable bad RAM in a running system, really wide system buses for pushing around a lot of data, and was built to survive physical abuse.
The trouble is, they lost out to "good enough". Solaris on SPARCstation was better than WinNT on a whitebox PC, but WinNT on a whtebox PC got to the point where it was good enough, and the added expense of a Sun workstation couldn't be justified. On the server side, Linux became good enough, IBM and Dell x86 servers got to the point where they were good enough, and my 13th generation PowerEdges are definitely better build quality than the Sun V245 servers I still have sitting in a rack for nostalgia.
This took away a lot of their revenue so they couldn't throw resources at research and development. In particular, SPARC fell behind in price/performance/power consumption trade-off, first to AMD's 64-bit Athlons, and then to Intel's post-Netburst Xeon. The UltraSPARC T gave them a bit of a reprieve on highly parallel workloads, but cancelling the Rock was the right decision as it was painfully obvious it wasn't going to compete for single-core throughput/latency performance.
They also lost at the extreme high end to IBM who've managed to get insanely high throughput on POWER with a brute-force approach of throwing better and better cooling systems at a design that's arguably incredibly lazy compared to the E5 Xeon.
Yes, I miss Sun, and I'll shed a tear for Solaris. But I don't miss the Sun that Oracle bought - the Sun I miss had already faded half a decade before Oracle bought the dimly glowing remains.