I was told that it comes down to the chipset makers, to the patent holders and how much money they can cream out of the handset making industry - for the most part they WANT a limited number of frequencies per chipset because that way they can sell more chips.
Hence the multiple SKUs based around the perceived demand for frequencies - 900/2100 goes together, 850/1900 goes together predominantly because of the larger markets and their needs.
It's only fairly recently (since the iPhone 4 I suggest) that demand for a phone capable of multi frequencies has reached the point where the chip makers are happy to make pentaband or more.
The idea that Vodafone or 2Degrees or anyone specifically buys handsets that exclude Telecom XT is a red herring - there simply aren't that many handsets out there that have that kind of capability.
Paul




