There are predictions and there are predictions. There will always be those predicting that strong AI is a decade away, right until the point when the last group is actually right about it.

But there's a different kind of "prediction", which I think is the type those smart people subscribe to - that we are on the path to an AI, that there's nothing that would make it impossible to achieve as the technology progresses (a reminder: we have a working example that intelligence can be built - our brains). Of course there are a lot of obstacles on the way. Personally, the most probable is that our civilization ends before we reach the necessary level - because of war, or all the economic and political shenanigans we see every day.