I saw the same arguments in this thread when the Office Ribbon was being developed. Self-described "power users" demanded an option to use the previous UI (which would have been a totally stupid thing to do), and declared that Office 2k7 would fail if Microosft didn't cave to their demands.
Go back a couple decades, and the same arguments were being made by those that decried GUI and declared that command lines were the height of UI design.
I recall similar arguments when Apple became the first computer maker to drop support for floppy disks.
I'm not even sure what the big deal is, since the complainers in this thread can easily program their own start menu in about an hour. Maybe you guys can use it as a business opportuinty and sell your solution to the public. Those that don't want to or can't program their own start menu can use Stardock's already available start menu. Another option is to just pin frequently used apps to the task bar so that you can avoid using start menus or start screens altogether.
Back in the day, I was of the mindset that software should provide all sorts of user options (e.g. an option to turn on Start Menu, or an option to turn on the pre-Ribbon UI in Office, etc), but I changed my mind a few years ago. Adding user options adds bloat and means you have to maintain multiple settings going forward (for example, forever maintaining the old menu/toolbar UI in Office would be assinine), and lots of times it indicates a lack of confidence in what you're doing. Rather than do that, you do the real work to determine what is better, and then go with it.