Qualified immunity is what prevents you from personally suing each member of the planning commission to pressure them in to reversing their decision. Think of it like the legal system throwing an exception, we aren't even going to consider this because your beef is with the city not an individual employee.
Police have qualified immunity because otherwise they would face personal lawsuits every time they wrote a rich guy a speeding ticket, or a convicted murderer has nothing better to do but get his law degree in prison.
In my opinion, qualified immunity is _not_ the problem. If an officer does something in their official capacity that is wrong, it is up to the department and the DA to deal with. Just like if the hypothetical planning commission did something illegal. Unfortunately police unions prevent that from being a viable option.
Getting sued is expensive, stressful, and time consuming no matter how the case turns out.
If you sue all the commissioners every time they issue a decision that you don't like sooner or later they'll see your next request and think "Can I afford the inevitable lawsuit if I say No like I should?" and/or "Can I take the stress? Can my family?" So next time they'll give you what you want just to avoid that whole mess.
IANAL but it sounds like qualified immunity is intended to short-circuit this: even if you made a reasonable mistake here and there you can't be sued by some bullying jerk.