Consequences of low approval

Ive been wondering if theres any problems with extremely low approval worlds, say 10% and even lower. Of course you dont get the bonuses from having high moral then, but is there any big problem with leaving a world that unhappy? For example a size5-6 planet i built only factories on it and poured its production into a shipyard. Seems the only penalties are -20% lower growth, influence and resistance...all a non-issue on a back waters production planet. Whats your preference for handling borderline worthless planets like that?