Which leads again to the question: What would be the business reason to do that? What would be the benefit for Nokia doing so?

To those still concerned about Qt in the hands of Nokia: big successful businesses might be evil or not, but if they are indeed succesful is because the steps they make generate benefits & profits. When thinking about evil possibilities make sure you find a potential business benefit tied to it. If you can't, then perhaps that evil possibility is unlikely to happen.