I've said this numerous times so please forgive the repeat:

Nokia TRIED to change the US model. Competitors saw an opportunity to grab market share as Nokia worked toward a more open, retail-based service. The effort worked against Nokia and in favor of LG, Samsung, Moto, et al.

Cracking the crazy US market would take more than Nokia-- it would take the combined effort of every single manufacturer getting on the same page and standing tough (or the FCC and FTC doing their jobs). I don't see that happening.