I think it depends a lot on age/experience and how you got into development. In my case, I'm relatively young, lack a college degree, and started out in sysadmin and, shortly thereafter, operations engineering roles. I've discovered good ops people are a pain in the ass to find, and I had the misfortune to be very good at it, so I naturally keep getting already-"running" systems dropped on me with instructions to maintain, fix, and interface with them. I've only had one true greenfield project (still in progress) since I started getting paid for my work.

Most of the other developers I know are older, have computer science and/or EE degrees, and have been around the startup block a few times, and have several greenfield projects under their belt.