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.
An anti-slapp law provides a short-circuit motion to dismiss. But the legal merits are still evaluated–just much earlier. An anti-slapp motion basically says: "Even if everything the plaintiff said were true, it's not legally actionable so end the case now".
Qualified Immunity is insane because it doesn't require a legal evaluation of the case. Qualified Immunity (practically) says: "because this exact fact pattern hasn't been tested before, the officer couldn't have known it was specifically wrong. Since the officer couldn't have known it was specifically wrong, we don't need to go any further".
That means, a case dismissed because of QI doesn't even end up demonstrating that the fact pattern was legally wrong!