This is actually a really interesting point.
13 years ago, the Cluetrain Manifesto loudly told us that we should actually (shock) listen to what our customers actually have to say - even the complaints - without trying to pretty it up for the ears of upper management. It led to companies really listening to their audience and being able to build products that addressed the real problems of their customers, rather than wasting time building solutions for some idealised pseudo-customer.
Lo and behold - the customers loved it.
Is it time we started listening to our employees the same way? Everybody has a grumble or two. But rather than everybody pretending they don't exist, and hushing them up the moment they try; perhaps it's better to create an environment of openness. One where people are not afraid to talk about the things that aren't working.
If we are prepared to really hear what somebody else has to say, even (or especially) if it's negative; then we have a chance to actually address the problem and make it a better world for all of us.
Sounds like a win-win to me.