Here's my idea about specialization and the mistaken notion of being a "generalist." Even if you are very specialized, you will still need a scholarly base of general knowledge. You will still have had a general education in college, and will have pursued other minor interests.
On the other hand, if you set out to be a generalist, you will have no focus. You can't set out to be an expert in everything, because the task is defined too diffusely. At best, you will know more about a few more things than the specialist does.