Nokia was in this disorganized place where symbian was still making them money being "good enough" but increasingly clearly not the future, they didn't want to fully commit to Maemo, and meanwhile they were still doing well in the feature phone business. That's 3 platforms and no clear winner for the flagship.

I get the impression that internal competition combined with not enough coherent vision was what did them in.

That and hiring Elop, but so much was already in bad shape before that.