There was a lot of commercial software that either didn't have Solaris x86 binaries at all, or only had 32 bit binaries.
It was arguably "better" from a purely technical view, but cheaper beat out better.
A video that amuses me with respect to engineering culture and organization blindness is Cantrill doing a DTrace demo at Google in 2007 https://www.youtube.com/watch?v=6chLw2aodYQ. The audience seems completely unaware about the significance of what they are seeing. The length of time between Linux getting cogent tracing support is telling. GOOG could have single-handedly propped up an extra-Sun OpenSolaris community, and there would have been nice symbiosis considering their early container usage and how long that took to grow as well.
The commodity always wins. Never forget that.
The reason I think it didn't rise to ubiquity in the same way that Linux did is the lack of customization.
One can easily customize the Linux kernel for their use case (i.e. Embedded), compile it, add busybox/dropbear, and you have a decent starting point for an embedded OS. You couldn't do the same with Solaris.