Yeah, when I interviewe at Google, this was pretty much what I was told - one of the prices of writing "new, cool stuff" is that you get to support it, because no one else is going to be able to fix it when things go wrong.

Sounds as if that requires retiring systems when the developer leaves the company.

I would imagine that if the new thing makes the transition to being a successful, widely used service then putting a support team in place is a part of that. At the beginning though, when no-one knows whether your new thing is going to be a success or not, the dev team is it.