I agree it would have been better for developers if all systems had comparible specs.
But the fact remains the HD consoles have raised development costs 3-4 times the amount of last gen games without any way for developers to reap 3-4 times the revenue and profit.
I don't think sticking all FPS on Wii is the answer, I think developers need to diversify their product offerings (like Ubisoft) so they are no longer dependant on having a blockbuster hit to be profitable.