It's the fascinating history of branding. Apple invented the PC, but they poured their energy into selling the brand Apple rather than the term PC. IBM then came along with a machine called "the IBM PC", which sold a lot of units and was the subject of a lot of marketing. With the word PC as the actual name of the machine, the tendency to associate that term exclusively with IBM machines began.
(As I recall, the generic term for a non-IBM PC tended to be "microcomputer" or "micro" rather than "PC".)
That trend then leapt forward when Compaq started making PC clones. The clonemakers needed a word for what they were making. There was a time when you could call them "IBM compatibles", "PC compatibles", or "PC clones", but once IBM switched to PS/2 and OS/2 -- and proceeded to fade from dominance -- continuing to associate the word IBM with these things made little sense. Meanwhile, Apple wasn't trying to contest the term PC... instead they invented their own exclusive brand name, Macintosh, and sold the hell out of that.
So in the end the word PC ended up meaning a generic Intel box that runs Microsoft Windows or Linux.
Nobody bought the IBM PC because it was called a "PC". They bought it because it was IBM, and in the 1980s there was a saying: "Nobody ever lost their job buying IBM".
Yes, that's right. What I'm saying is that IBM successfully sold the term "IBM PC" because it contained the magic letters I-B-M. But then the magic slowly spread to the other half of the phrase IBM PC, to the point where PC eventually became synonymous with IBM.
(As I recall, the generic term for a non-IBM PC tended to be "microcomputer" or "micro" rather than "PC".)
That trend then leapt forward when Compaq started making PC clones. The clonemakers needed a word for what they were making. There was a time when you could call them "IBM compatibles", "PC compatibles", or "PC clones", but once IBM switched to PS/2 and OS/2 -- and proceeded to fade from dominance -- continuing to associate the word IBM with these things made little sense. Meanwhile, Apple wasn't trying to contest the term PC... instead they invented their own exclusive brand name, Macintosh, and sold the hell out of that.
So in the end the word PC ended up meaning a generic Intel box that runs Microsoft Windows or Linux.