No, not FUD...not really. Solaris is a complicated tale.
The short explanation is that when Oracle acquired Sun, all of the hopes and dreams of Solaris users, particularly OpenSolaris users, were dashed. Many great technologies were pushed onto the back burner. All of Sun's Open Source portfolio saw a massive shake up and very little came out the other side healthier. Pre-acquisition, Solaris/OpenSolaris was a reasonable OS choice for new server deployments, particularly in cloud environments. Post-acquisition, you'd have to be a little bit nuts to deploy Solaris. Solaris has a lot of die-hard fans, with good reason...so this was a bitter pill to swallow for a lot of folks.
Oracle is simply ham-fisted when it comes to dealing with Open Source technologies that it comes into possession of. It's a really good example of a company that doesn't "get" Open Source. It's not limited to Solaris, Solaris is just one of the most popular, and the most difficult to replace for people who are relying on it.
I am a long-term SunOS/Solaris user (~20 years) and what killed Solaris is they neglected Solx86 for years for fear of cannibalizing SPARC sales. What happened was devs got Linux boxes to replace SPARCstations (using them as cheap X servers) then x86 and x64 got good enough for servers, and everyone ditched Solaris in order to get onto the commodity hardware (Linux wasn't really a factor in this decision, it just happened to be the dominant Unix on that hardware at the time, could easily have been FreeBSD). Thanks to Microsoft and their NT pretensions, supporting hardware vendors (e.g. storage) were manufacturing compatible kit too. It didn't help that Sun managed to forget that they were a business, and a hardware business at that. Giving stuff away to drive sales is a proven strategy, but no-one was buying SPARCs. Turns out it was cheaper to buy PCs and accept failures and workaround them, than to buy a "real" server that wouldn't fail and if it did, you could hot-swap anything. Call it the Google method.
Sun could have had a compelling desktop-to-datacentre story, all Solaris, on Intel PCs all the way to SPARC near-mainframes. But they succumbed to short term thinking and killed the goose that laid the golden eggs. The alternative to the Oracle acquisition was for them to go the way of SGI...
