Andy,

I think it's not entirely clear what exactly you mean by "specialization." In my post, I'm not addressing the question of when (if ever) it is advisable to stick your nose into topics outside of your own area of expertise, which is a fascinating topic in its own right. Rather, I am assuming that you have decided to do so and that your goal is to form a maximally accurate opinion about some such question.

So overall, I think my post is orthogonal to the issue of how much you should push yourself towards specialization, except insofar as it stops being relevant if you decide to pursue the most extreme and absolute specialization possible.