I would disagree.. Two disk RAID 0 is about twice as fast as one disk, which is very addicting. Importance depends on how you use the computer, but if an active user, it is hard to ever go back to single speed. For example, a Photoshop batch processing 100 RAW images? Perhaps those that won't try RAID 0 are simply missing out on a good thing?
Complexity? Everything is always difficult for a newbie, but this is just a menu. Automated and invisible after that, the disks continue to do what disks do. Except the speed is always very noticeable.
Reliability concerns are greatly overstated. The concerns are that two disks have more risk possibility of failing than one disk - two changes to fail instead of one chance. But the disk is likely going to be good for a few years, and it is really the same risk as if they were separate. True, RAID 0 disk failure does have two chances to bring down your system disk, but even if separate disks, you have the exactly same two chances of bringing down something, either the system disk or the second disk. If a disk fails, it fails. You simply keep it backed up, same as in any system, in case a disk fails.