Honestly, I sometimes wonder where some of you people come from? You're supposedly long-time Apple users, yet you don't seem to remember a single thing of Apple's history?
The ORIGINAL Macintosh, for example, was a PAIN to take apart! You needed a special, super-long torx wrench, just to access the torx bolts they sunk DEEP into the plastic case. (Not like torx bolts don't discourage people enough from taking something apart - since torx drivers still aren't anywhere NEAR as common as normal screwdrivers. But they had to go and make sure no normal torx driver on the market would ever REACH those bolts!)
Apple has a LONG history, ever since that first Mac, of building machines that discourage people from disassembling them or doing their own upgrades to them. At the same time though, they interspersed that with very easy-to-open machines. (Anyone remember the old Apple LC series? System looked like a plastic pizza box, and the whole top of the case just snapped off by pulling on two tabs in the back of it!)
In that respect, it seems like nothing's really changed a bit, over at Apple. They're still cranking out the random machine that's easy to work on, followed by one that's not. And above all, you can bet they'll make almost every one of them a new "learning experience" to work on. (Look at the insides of the iMac G5 machines for example, vs. the first (same white case) iMacs with Intel CPUs. The insides look all clean and neat in the G5, but a hodge-podge packed in the Intel version.)
More examples? How about the G4 cube, with the cool way the whole insides slid out of the top shell, just by pulling on the big release handle on the bottom? Compare that to a Mac Mini, where you need a PUTTY KNIFE to wedge in there and pop the sides loose!
It's almost like their designers have split-personalities and you never know which way they'll swing when they do a given system revision!