actually you're wrong people who want DX 12 for gaming and all the fancy metro crap and touch thingy, will switch to "win10" anyway but by releasing SP2 for "win7" would force MS to support the OS with SP2 even longer this way they are cutting it loose in ~3.5 years, as they don't want another XP scenario
I see no more good things with Windows 7 since Microsoft has started delivering telemetry updates to 7 too