Jorgen - You bring up really good points. I'm actually working on an article on this exact topic. It was too much to fit into this article.

But, it is interesting how well extreme specialization works and how many people like variety and would get bored with too much repetition. I am not sure what the right solution is to this tension.

On the other hand, I think there is A LOT further we can go to become more specialized without getting in the boredom zone.

For example, one thing to point out is that many people are being generalists in sort of a forced way. They're doing things outside of their specialty that they don't actually want to do or enjoy doing. This is very different than people learning across fields they're excited about and then using that info to specialize in one area.