What’s the biggest problem with perfectionists? It’s that they don’t know they have a problem!
Perfectionism is a habit that people are proud of, even when it causes them anxiety and trouble. This New York Times article describes how being a perfectionist can lead to mental health problems and even suicide, not to mention garden variety unhappiness and stress.
In the areas of time management and organizing, I see people abandoning or not taking on projects at all because they don’t believe they can do them perfectly. Or spending disproportionate amounts of time on tasks that are very low priority, but capable of being "perfected," while avoiding more important, unperfectable tasks.
The article mentions several aphorisms that perfectionists live by, such as, "Never accept second best." Another one I hear a lot that I disagree with is, "Anything worth doing is worth doing well." Baloney! Plenty of things are worth doing just adequately so you can get on with the really important stuff.