Correct. Here's the requisite car analogy.
I recall several years ago seeing numerous Nissan sports cars in the "for sale" section of the want ads for amazingly low prices. These cars had about 20K miles on them and were going for several thousand dollars below blue book price.
So I started looking into it. It seemed that they were a good deal up front, until you find out that they all needed tires.
Seems Nissan sold some cars with a proprietary wheel rim size. You could only get tires from one company and they wanted nearly a thousand dollars a tire.
Nissan created an artificial scarcity by introducing a proprietary requirement with no good technical reason.
Likewise, Apple requires EFI to boot OSX, although there isn't any technical reason to do so. They could have used the standard IBM-type BIOS or something like OpenPROM, but they chose to introduce an artificial, non-technical requirement in order to restrict what PCs their OS would boot from.
This is quite apparent when you see the hacks that allow OSX to boot on generic PC hardware.
BIOS is antiquated, that's technical reason enough. It's 16-bit, is tied to old AT hardware and can use only 1 MB of memory. Think if Nissan moved to new light-weight rims. EFI allows Macs to do things not available on PC BIOS systems.
BIOS is the main legacy left in PCs. Sun has Open Firmware, IBM has RTAS, Apple and Itanium systems use EFI, and there are others out there. Now that Vista finally recognizes EFI (Windows for Itanium was the only one that did before), expect to see BIOS slowly going away.