Yep, and I hate it when they use "PC" as a synonym for Microsoft Windows. I do have a PC!

It's Apple that made PC synonymous with Windows machines (with all their "Mac vs PC" ads). Yes technically speaking it's incorrect, but that's human language for you, it just happens. Sometimes the other way round, eg. walkman was once Sony's tradename, but eventually all portable cassette players were called so.

Not really, it actually comes from long before that.

I remember being a very little kid and buying shareware games with their "PC-Compatible" labels. At the time, that sticker actually meant "DOS Compatible", and being I just about 10 years old, I believed PCs and DOS were the only possible match, the same way my first MSX ran MSX-Basic and my cousin's Amstrad CPC ran CP/M. I didn't know it was even possible for machines to run different OSes. For that matter, I didn't even know what an OS was. I just knew different machines worked differently, the same way different TV sets worked differently.

So it's not just a matter of human language, it's a matter of intentionally confusing terms in favour of the market. Everybody knew there were other "walkmans" around. Not everybody knows there are other OSes.

Clearly Apple subscribes to this terminology, and I don't think it has much of an interest in putting forward the impression that Windows is the only option on PCs and concealing the existence of Linux.

I think it does. From the very beginning they wanted to sell computers to people by making them think they work like home appliances. If people knew computers are actually universal machines, then they wouldn't be as willing to pay more for the same components with a different brand printed on the machine's case, or a different software running in them.

Besides, that gives them a single competitor to fight against.

Is it really easier to face one big nearly monopolist opponent instead of two who're fighting against eachother? Also one important obstacle for the adoption of Apple products was the common notion that there's no plausible alternatives to buying a PC. That's why they invested heavily in sending the message of pluralism - "think differently" etc.

Yeah, and a Mac is a PC, internally speaking too. So, it should OS based : OSX, Windows. This, coming from the number 1 tech company in the world. Kinda disappointing.

Yet somehow everyone understands what people mean when they say "Mac or PC"...

Prescriptivists.

This has nothing to do with prescriptivism whatsoever. This is like calling the blue "e" icon in your desktop "The Internet". It's just plain wrong naming.

In tech, things should be called by their name, or you risk future confusion.