NO, that's not strategy - that's brute force (or better... 'was', as it's dated back 2002 or so)
early Mac OS versions completely ignored the mac type
customers used to 'update' their existing boxes with the software that came with a newer machine, they just claimed the right as considering themselves well-paying loyal customers...

maybe not perfectly in line with legal terms, but ok with us resellers
'installer' bs didn't exist yet on Macs
of course Apple couldn't miss what what was going on, so with the 90s we got installer CDs, version checking like '...is not compatible with...' bla, bla
all rubbish, just copy an OS from a running machine to a 2nd harddisk and use the latter (containing the very same version that 10 minutes ago complained...) in the target box.
The OS was smart enough to deal with all machine specific items at runtime, it only created a machine specific version on request if you wanted a system folder as small as possible - which was pointless as harddisks were pretty large already.
when Apple released OSX it was of course bundled with every new machine, and you could choose between the classic Mac OS, OSX or double-boot.
Apparently almost NOBODY in their professional customer base (publishing and media production) switched to OSX, as there were only disadvantages and it was something to mess up workflows that had been established over years.
Never change a running system...

to be honest, every version of OSX before 10.3 was just a piece of crap...
again this was hardly to be missed in Cupertino, so they finally decided to the last resort:
since 2002 the Rom code refused to boot anything but OSX, effectively removing the choice (that had always existed) from the customer.
It's an unparalled decision in the company's history, the final sign that things had turned into another direction, ... and it s*cks
cheers, Tom