This is a negative that must be fought as fervently as the Alt-Righter who wants to supposedly go toe-to-toe with the local chapter of Antifascistisk Aktion over whether dear Emperor Trump represents the fascist take over of America or not.
Much of this is a result of what we can call institutional inbreeding or inertia. By this I mean that without any outside frame of reference for things like 'tactical training,' we are selling ourselves short due to the limited exposure. Without a healthy appetite for learning and a passion for the continual search for knowledge, people do not progress. They stalemate or worse, they retrogress. In practical terms we fail to be the best we can be yet we convince ourselves we are studs.
This phenomenon can be seen all through out both the mainstream firearms training culture and the Threeper subset in particular. People take instruction by one person or company and it ends there. Or they have one 'expert' they go to for everything.