Solaris is an actual System V, not a clone like Linux distros often are or a BSD.

It's got excellent support for compiling software written for different UNIX systems.

It does a lot of things with commands that other systems do with config files.

But no, there really aren't any compelling reasons why a non-hobbyist would be interested. If Oracle had continued development on OpenSolaris then yes, but they have little interest in their own version of Solaris.