It may be human nature for people to talk about each other, but that doesn’t mean you have to put up with it. It is impossible to create a unified team with a bunch of gossips. Gossip pushes people apart instead of pulling them together, and everyone knows you can’t trust a gossip.
If a team member is discovered gossiping, they receive one warning. After that they’re fired, and, yes, Dave has fired people for gossiping and will do it again to keep it out of his company.
Negative stuff will happen. That’s inevitable. The negatives may be about a person or a process. Either way, those issues need to be handed to a leader. If you’re mad at your manager, talk to another leader about it. Complaining to your teammates is disloyalty, and it fosters a negative spirit that will trash the organization.
Dave and his team have a motto: Negatives go up; positives come down. Team members love it. They not only adhere to it, they enforce it. They are, after all, the real beneficiaries of that policy. They can point to that rule with pride and cut gossip off before it has a chance to do any damage.