This phrase exemplifies the power of exclusion.
I heard it from a successful businessman. He started many projects and companies on his own because he was shut-out from other opportunities. By keeping him out, they created their own competition.
By excluding people, you create impediments to your project’s success. It affects driven and capable people the most (who are exactly the people you want on your team, the linchpins).
Take the time to listen to people on your team. Make people feel included.