Should Microsoft Break Compatibility with Pre-Metro Programs?

I know that many businesses use programs that are not currently available/made anymore, and I believe that it is great that Windows 8 supports them. But the difference between applications designed for Metro and programs designed for Aero (or even older) is very jarring. I find it very hard to believe that developers are going to automatically make the switch if Windows 8 supports their program.

What I am asking is that would it be better for Microsoft public relations wise to break apps that were made pre-Metro. I know that Microsoft gets blamed for lots of issues that are not necessarily their fault and that this "solution" will incite great irritation, but will the benefit out weigh the gain? The programs could still be accessed through something like a "Windows 7 Mode".

Should Microsoft break compatibility with programs that aren't Metro starting with Windows 9 or Windows 10? I have recently seen how much reverse compatibility has held Microsoft back. I think it would be better for their ecosystem as a whole if the broke compatibility sometime in the future.