lack of progress at local towers I think you are mixing up several things. Devon ringers ring call changes well and many bands who see methods as the norm produce ringers who can't strike well. Correlation isn't causation. In method land lots of bands strike call changes badly, and bands that consistently strike well tend to be bands with a good method repertoire. That suggests the opposite correlation, and proves that what is being rung isn't the point, or at least not the main point.
Preceding comments were about rope following, holding up and ringing by numbers. That's far more significant. Look at how many people are taught to ring, introduced to collective ringing, and given advice while ringing. It is dominated by rope following and not by the need to developm rhythmic bell control and listening skills. Is it any surprise that so many ringers develop non rhythmic, non hearing, vision dominated habits, and only a few manage to pick up the essential core skills despite how they are taught.
I would say the culture in a crack method band is much closer the the culture in a crack call change band, a focus on striking as the objective and developing the skills needed to achieve it, than it is to many bands and ringers in method land. To change the result we need to change the culture, but that is hard because new ringers are infected by the existing culture of the bands they join.