Sure, I understand your basic philosophy but it's a little simplistic. I wouldn't let a great brain surgeon fix my knee even though they both went to med school. Just like you wouldn't let the guy down at the bike shop work on your car. And I sure wouldn't let the guy down at the ford garage do more than put air in my bike tires. Good mechanical skills are just the foundation, you still need specific knowledge and practical experience.
Agreed,to a point but there is a reason bicycle mechanics do not get paid much compared to other mechanics. Bikes are just not very complex. I would not have a problem letting most motorcycle mechanics work on my bicycle but not vice versa.