If Nintendo had supported Wii even longer then WiiU would have even less games ready.
Nintendo only took Wii out of the market when it was barely selling anymore, but SW support they removed long earlier and that is a possible cause for the sales of HW to plummet so hard.
They didn't need to support it at 100% of their dev power. Just enough to justify it being around. Hell, they were swimming in buckets of money back then, they could have paid other studios to keep quality Wii games coming, or just open more studios and let them experiment with the Wii, it's not like they needed to make the system sell at this point.
You know it deserves the GOTY.