It's a start. Adding the safeguard doesn't mean effort won't be put into fixing the actual bugs. But you just don't fix all the world's bugs overnight. That's why things like virtual memory, permissions, chroots, ASLR, NX, SSP and such exist.
How many systems enable core dumps by default? I don't actually know, but I think quite a few do. Every application you use to get stuff done is a production application. Every application that handles sensitive information handles sensitive information whether it is in production or not. Leaking passwords and keys can be as simple as working on some client software, having it crash once, then passing through airport security and getting your HD snooped on...