Private investment is what means perverse incentives. You care about your big donors now. If you take 50k from a guy you want to give him what he wants in return so he gives again. It's about ROI. The bigger the amount the more strings attached.

Public trading means clear protocol for ROI and it allows to have many small investors who can have as little say as you specify (non voting shares etc). Comes with requirement for a lot of documentation and transparency too. So accountability. If business I like wants to grow and needs money this is the route I want it to take