I have no idea if specialization leads to a form of weakness. Many of the programmers I've met have been highly specialized - not just in language, but in the type of problems they solve with that language. Within that specialization, they do things that are stunning, and possibly a little annoying (smug so-and-so's).

I'll probably never know, though. A short story from Robert Heinlein had a profound impact on me when I was growing up, especially a single line:

Specialization is for insects.

Every time I wonder "why should I learn tool/trick/thingy Y, when X already does the job nicely?", that line pops into my head. So here I am, stuck knowing nothing about everything. Maybe it's better than knowing everything about nothing, though.

"All you need is ignorance and confidence; then success is sure."-- Mark Twain