Agreed, I see that happen all the time, especially with chat platforms for some reason. That's why I also said discipline. Having run large forums the temptation to make rules and power-trip is human nature. The biggest battle is with ones self and not letting others help moderate unless they share the same discipline. Finding people that share the same values and are not at risk of power-tripping is hard. Assistant mods would have to know up front they would be booted as soon as they exhibit such behavior.
I would suggest people first start up some little just-for-fun thing and learn the hard way what the biggest struggles are before creating something they truly are passionate about.