Comment 11 for bug 811485

Ah, I see what you mean.
HP appears to be breaking that paradigm, however, in that they have UEFI firmware that supports "legacy mode" booting, and that they seem to be shipping systems with normal MBR-style partition tables that nonetheless have EFI boot partitions.
My understanding of how Windows boots is, I think, the same as yours - although its legacy boot mode is very similar to EFI boot now, it's still different. So WTF is/are HP and Lenovo and Acer [I think], and... etc. doing?
The existence of this hybrid non-GPT-but-still-EFI firmware and accompanying boot process, unless I'm missing some important detail, will require that Ubuntu and others abandon their very limited notions of UEFI-compliance and allow much greater flexibility.
Meanwhile, I'm thankful that the Ubuntu systems I manage still have the ability to boot in 'normal' legacy mode. (As does the HP 8200 - if you're willing to wipe the existing disk, everything works just fine.)