That's not the point they're making. What they mean is that if they consider side projects as potential criteria for being hired or not, they'll lose the fun in those side projects.
Because they'll then try to make every part of the code perfect and with complete documentation for everything, probably spending more time trying to present it rather than working on it.
Because they'll then try to make every part of the code perfect and with complete documentation for everything, probably spending more time trying to present it rather than working on it.