As for this guy who's going on and on about scalability:
-You are generalizing scalability between several, very differently built systems, built for very different purposes and using that as evidence for Solaris superiority. Linux has blanket market share here, that is reality.
-In your defense, many sysadmins agree: "If you care about your data it is on ZFS." ZFS is solid, possibly the best product to ever emerge from Sun. That doesn't mean that the hardware will survive a natural disaster. Linux filesystems on RAID with enough redundancy will grant you the same amount of reliability and performance as ZFS- just in ZFS' case, you just need less redundancy. Big friggin deal when you're spending a few million on a number crunching, I/O munching server.
-Finally, you seem to forget that the kernel and filesystem developers develop kernels, filesystems. They're designed to be versatile for common use cases, not exotic use cases. How they are used is up to the implementer and users/sysadmins will always surprise you with new use cases, some of which you cannot readily test.