As a card carrying MBA (Class of '84 from a top 20 in the world institution) your comments regarding the worth of this qualification are both correct and incorrect. Any decent MBA school will send you off with a reminder that an MBA is a licence to learn management.
Unfortunately companies are stupid enough to hire "wet behind the ears" MBA's into roles that are outside their capacity. I know. It happened to me. Picture a 28 year old Sunfish advising a grizzled 50 year old how to run his business. I cringe at the thought of it now.
The real issue, I believe, is that we have now substituted "Character" as a precondition for a management role, with "Merit" which has come to mean "performance"(including an MBA) in a narrow set of dimensions. There are plenty of "Industrial Psychopaths" who do "merit" very well, and therefore get promoted to where they can do considerable damage to an organisation.
Of course in the bad old days, you hired someone you had been at school with, they may not have been very bright, but at least you knew whether they were a s**t or not.
It's your call which system for selecting senior management works best.