When was the last time you installed from a bootable tape?
I haven't done it since HP-UX v9.04. EVERYTHING, and *I* mean every *NIX system I have installed booted from CD or Network to start and Install. The same could be done for and upgrade on most "commercial" *NIX.
I usually chose the Online upgrade packages as needed and wanted approach. I never did fully upgrade from AIX 4.2.0fp6 to AIX 4.3.3fp9, as the only real differences were the packages for hardware support. HP-UX, the upgrade from v9.0x to 10.2 was really simple. Put the CD in while running you system and do a "upgrade when possible" style of upgrade. Allowed me to do the upgrade in the background as people were using it.
Oh the last time I booted from a tape was to do a system recovery, which BTW, was easy cheesy. This whole thing about getting away from traditional UNIX is easy in talk, tough in practice.
Easy to install == typically a nightmare to maintain
PITA to install == typically a dream afterwards
That holds with most "R&R" aimed operating systems *ARE* indeed easy to install, you wouldn't want John Q Public Paying for "R&R" support, would you?
That also hold, with most "Install and Maintain" aimed operating systems, they are nearly self maintaining. Then again, you wouldn't have this "revenue base" to rely upon.