Nokia wants control over the roadmap of its software platform. They certainly don't want to do anything that might risk them being put into a position of being

Nokia wants control over the roadmap of its software platform. They certainly don't want to do anything that might risk them being put into a position of being a commodity hardware manufacturer. You can argue how big of a risk that is if they adopted Android, but that's probably the thinking behind avoiding it. Personally I think it's a smart move for them, if they can execute well. Even when Symbian was a consortium, they didn't want Symbian to do doing a lot of things (the UI team was one of the first to get the axe when a first round of cuts occurred). There would also be political battles about whether Symbian should be implementing other aspects of the platform.