You make a pretty good point and I'll ride this one out. Piracy was everything.
The idea was that IBM PC Compatibles won for a lot of reasons. But the clone market and piracy was the real reason. I remember the first time I saw the original manuals for an iBM PC 5150 and I was shocked that one manual was gobs of printouts of the source code to the PC BIOS. The Compaq made a clone very EARLY. CP/M was way too damn expensive... I can go on and make a history lesson, but the people old enough to remember have their own versions of it and its not worth it.
Over all, the PC won because we pirated the shit out of everything. The PC clone itself was basically a pirated computer. There were arguments that the NEC v20 processor exceeded the agreement with Intel for "second sourcing" and was technically also pirated.
Anyway, the path was simple....
The company dad worked for which was an IBM shop bought IBM PCs and used DOS, Wordperfect, Lotus... maybe a little later on Act! and allt he software cost 3.5 metric butt tons. Then dad pirated the software and rather than buying Wordperfect, he bought an aftermarket keyboard template or similar for how to use it. The his nerdy kid who was pissed dad bought a monochrome terminal (because CGA hurt your eyes) played on GW-BASIC and Flight Simulator (the only program dad actually paid for to make up for not getting a commodore, atari, Apple....) and a LOT of houses ended up with PCs.
But the point was, a IBM PC clone with two floppies, hercules, MS-DOS, and a screen and keyboard was A LOT cheaper than ANY Xenix system if only because every single aspect of the computer was pirated except for the one program you actually paid for which was DOS which was almost free. Especially when that was pirated too.
But PC happened because
1) Developers got PCs because they wanted to write software for the only people who actually paid for it which was companies and the occasional oddball who actually bough a genuine IBM PC.
2) PCs had a crap load of RAM (except the actual PC which never did)
3) When graphics happened, Autocad and every engineering software company coded for the computer with a lot of RAM
4) You could slowly play less sucky games on PC which made it so Junior at home was willing to not burn the house down.
5) Most importantly, copy protection never worked, Copy II PC Deluxe (also easily pirated) happened, and no one paid for software.
Xenix and Unix couldn't happen because unlike modern Linux, every single thing about it sucked. It was so incredibly shitty. A/UX probably was the only Unix ever shipped which didn't absolutely suck. And it sucked.
I don't think modern kids could ever understand how impressively shitty UNIX was. I can't believe it took us until the 1990s to get a shell that had history.