Provided proof? What proof?... you said that with some hacks the WP8 tools can be installed to WP7 and they run. I've seen no proof of that here. More so... even if they do run and support deploying to and debugging against a device... doesn't mean everything still works.
For all you know, there are some features (other than the emulator) that require Windows 8. I don't know if they exist, I have just seen cased like that over the years, and when you say things like:
I understand that I hit a nerve with you working for Microsoft and all, but...
The proof I provided has nothing to do with the hacks I mentioned. I just added it in there because it is another way to prove my point.
The actual proof I provided is that on a Windows 8 OS where the hardware doesn't support SLAT, the WP8 installer will simply warn you that the emulator won't work, then continue to install the SDK. So this proves that the reason you can't install it on Windows 7 has nothing to do with the emulator being able to function or not.
It is some other reason...
EDIT: And as evildictaitor mentions, it is one thing to not support much older OSes, but Windows 8 was barely out the door and off to a poor start and MS limits the WP8 SDK to it and only it? That is not the typical requirements when MS releases products.
I guess one of the reasons is probably to sync up WP8 and Windows 8 development, what with all the unbelievably great experiences with having a broken desktop and Metro rammed down our throats. I mean, some way or another we will all get to fall in love with The New Way.