Windows is a joke
Amen to that.
Linux is a joke
Linux makes the sun rise in the morning. Without the Linux kernel, we'd have no stable or reliable servers. Sure, we've got OS X Server now (massively overpriced but there you go), but back in the days of the dot-com boom, Mac OS would crash upon Jupiter aligning with Mercury or if the microphone picked up naughty words that it didn't like, and there's no way any self-respecting server baron would use Windows to host a website over two megabytes in size. It's still the case, even to this day.
Not everyone wants to have to take apart their computers all of the time to upgrade a bunch of shit.
Not everyone, but it's nice to know that if you wanted to, you could go and buy a new processor and only throw away one old processor rather than an entire system, which is kind of a waste really. Sure, you could sell it, but what do you do with it a decade down the line? It's obsolete by that point.
I'm thinking maybe that many of you haven't really looked into the PC in great detail. It's a good platform. Windows is a bad OS that happens to run on it. They're two very different things.