What is it with Sega fans? They feel the DC was wronged by Sony so now Microsoft is their new standard-bearer?
The thing is, Sega had a collaboration with Microsoft on the DC didn't they? Developers could code to the metal using Sega's APIs or use Windows CE, as was done for Sega Rally for instance (but as I recall, most people thought the Win CE games performed worse).
As with many Microsoft partnerships, MS later goes into the same business, in effect becoming a competitor (except here, Sega went out of the hardware business).
These game company allegiances are trippy.