When folks come to you with ideas or suggestions for change, the stuff that drives those ideas is energy. Creative energy. And creative human energy is perhaps the most valuable thing on the planet. It's the stuff that moves mountains and gets spacecraft to Mars. Creative energy should not be squandered.
In the face of a new idea, the worst possible response is to shut it down completely. In other words, to say no. "No" kills creative energy. It kills it in kids and it kills it in employees and it kills it in constituents.
When folks come to you with ideas, with creative energy, I believe it's the responsibility of those in power to harness that energy. Direct it. Channel it for good. With creative energy comes opportunity. This is the hard work of management--reconciling the varied and diverse interests of varied and diverse stakeholders.
*** Maybe you can't say yes, but you can say yes to something else. ***
So, in the face of an idea, suggestion, critique, or complaint, take advantage of the situation, see it as an opportunity to harness creativity to do something cool. This will likely require some humility. Perhaps a lot of humility. You will likely have to give away power. You may lose some control. But you also may be able to do much more than you would ever be able to do alone.
Relatedly, beware of those who always say no. It comes from a place of fear. A place of weakness. It comes of apprehension over losing what little power the nay-sayer believes they enjoy. And when you hear no, realize that, often, what you're actually hearing is a response driven by fear. Fear of losing control. But understanding the origin of that fear may lead to a way forward.