I've seen devs come and go. They start on a project, rewrite whatever they can get their hands on into the "way it should've been" and then fuck off after a year. The devs that stay have to figure out the maintenance story on their own because screw comments and documentation for this new bright and shiny way of doing things. I don't know if I'm the only one that sees the pattern in our company but God forbid you say anything to bruise the new hire's ego.