Sure, pick the silliest-looking case you can find and claim it's a typical PC.<p>Apple is able to make everything slot into the motherboard because they control the design of every part, and sell enough volume in that exact configuration. There's no standard place on the motherboard for your hard disk connections, so you can't do the same for arbitrary motherboards.<p>You could sell a PC case that only took one motherboard, one that hard drives slotted directly. But realistically, once you've chosen the motherboard that severely constrains your choice of processor, and probably memory as well. It would mean giving up everything that makes the PC great.<p>And really, who cares? The engine bay of my car is pretty ugly too, but it's not like I'm showing it to guests; when I pop the hood it's because there's a specific problem I want to fix, and as long as it all works it doesn't matter that it looks like a mess. The inside of my PC is exactly the same.