Cant belive im saying this, but in their defence....
they are trying to make money. I think posting windows ISOs to the net would make piracy easier than it already is... but you cant pirate windows by downloading a service pack. I would be quite happy with always having a servicepack-current... which can be slipstreamed by the user to create a completley up to date disk the way service packs already can be.
althought if they started posting completley up to date windows isos I would certainly dl them