Why not? As far as I know, it's been at least somewhat successful in some other fields already. The other surprising thing is how different the sites can be while still having the same structure and UI.

I think StackExchange is sufficiently flexible to be useful to people who aren't programmers--it just needs time to branch out. Remember that StackOverflow was not only the first site, but also had a big head start in the form of Spolsky and Atwood's blog audiences. Growing a different, non-programmer audience organically is naturally going to take some effort and time.