Try organizing a party in a “Yes, but…” atmosphere. The result is probably a zillion obstacles identified, but no party.
Try moving through a door with your eyes stubbornly fixated on the door frame. People seemingly can become deeply obsessed with frames-as-obstacles.
Try benefiting from Scrum in a “Yes, but…” environment, where the primary response is to raise concerns and hindrances, where the conversation is all about obstacles, and that what cannot be done.