Who here expected Wii to make FPSes so easy that Grandma could play them like a pro on the first try? When did Nintendo claim anything other than that Prime 3 was for traditional gamers, or say that it was going to turn "casual gamers" (formerly defined as people who mainly played FPS and sports games, now defined as people who mainly play Mario Party and Wii Sports) into "expert FPS players?" I think the only "lies" are the ones you created in your own head and attributed to Nintendo.
I refer you to the vast swath of ugly rhetoric in Nintendo's E3 press conference and the legions of Nintendo apologists who have been running with it ever since.