You're speaking out of opinion not out of facts.
The reason your Mac "clogged up" after 3months prooves you don't know how to handle a computer, period.
Doesn't matter WHAT kind of machine you use, not one machine handled properly will "clog up" and "become sluggish and slow so it's unusable" after 3 months of use - if that happens YOU are doing something wrong, intentionally or unintentionally.
I've been using Windows and Mac OS X for the past two years, both machines runs smooth - a bit more issues with the Windows machine than the OS X one, but that's only because I'm more used to OS X and know what I want and can expect from the system.
The interface works, you have a "Start/Power Menu" "File, Edit, Show, History etc," a desktop, a launchbar/dock whatever you want to call it, integrated OS searching, everything ordered in a way that my mother can understand it - it's making apple tons and tons of money they have no reason to change it, same as Windows, the UI is the same as it was back in 2k, just a couple of more colors~~
So before acting all godlike and superior perhaps you should consider how YOU use a computer, because the way you sound and if the information you provide is correct you're either a biased asshole or need to rethink your profession.