What? I don't get your logic. What do you mean by viable and why do you consider RIM and Nokia to be viable when they're deep in the red?
If switching to Android didn't work for Motorola, Sony, LG, and even HTC(revenues and profits are crashing hard), why would it work for Nokia or RIM?
Competing in a race to the bottom with minimal customer loyalty(see HTC's lack of repeat sales) is not really viable.
Not the OP, but both RIM & Nokia had excellent sales channels (much better than Motorola, Sony or LG) and Nokia especially had fantastic scale to for their logistics chain. Nokia could build and distribute any phone cheaper than anyone else in the world. In the post Tim Cook world Apple may well have surpassed them there now though.