I've always thought that my particular strength, as a developer, is dealing with other people's (often poor) code. Maybe it's because I've spent more time in my career doing maintenance than I have doing greenfield work, maybe it's just the natural way my mind works, but I've always felt I stand out from the crowd more due my skill at debugging, fixing and modifying existing code.
So yes, I think I'm pretty damn good at reading foreign, messy and undocumented code. I've done a lot of it, and I've figured out problems that had my co-workers scratching their heads.
And I really would hate to think that anyone looked at my code and thought it was messy or undocumented! As CoolBeans said in his answer, maybe if someone has only been exposed to "unmaintainable code" that person will be more prone to writing bad code. But that's not the case for me. I've worked with fine coders, collaborating on excellent code, and I've maintained the worst of the worst. I know what the difference looks like, I know what I like, and I strive to write code the way I want to see it written - clean, clear and maintainable.