It comes down to semantics. If you're talking about closers that failed as major league starters and became successful relievers, then no, there aren't many that have done that, compared to those who wash out completely. Now if you're talking about people who failed as minor league starters, then you're talking about almost everybody. At that point I don't understand the point in bringing it up since it applies to everyone, and the topic of the discussion(Dempster) falls into the first category.