Here's the reality: Since tye 1960's B-schools have been pimping this idea that a good manager can use generic management principles any where and so will be good at any business. Even businesses which they don't really know a ything about. That doesn't tend to be true especially in complex businesses such as car making. Sure, any MBA can identify that a solid rear axel is cheaper to make than a rear multilink suspension but they seldom seem to understand the exact teade offs they are making in order to get those cost savings. In short, they don't know enough to know if the trade offs they are making are good or bad ones. Those cars end up dying a death by a thousand cuts and end up being the 1992 Oldsmobile no one ever wanted, who originally had to he sold at massive discounts (read loses for manufacturer) to get them off dealer lots, the people who drive them quickly figure out the car is garbage, and a few years later the brand dies because everyone has learned never to trust it. Btw Olds was the brand most dominated by MBAs at old GM.
Sorry, but the more you know about the business the better you are at running a business and generic "management principles" will not enable you to engineer a car customers want to buy. It helps if you know enough to actually know which compromises you are making.
First, I'm going to correct the stereotype that's persisted throughout this conversation of "the MBA who manages but doesn't understand his industry." My position is that an MBA who is valuable is one who is smart and learns the principles of an industry. As I said before, MBAs are perfectly capable of understanding how cars work, how to perform an oil change, and how to help streamline manufacturing processes. If you're an MBA and you can't understand how cars works, you're probably a moron and not worth hiring. Most likely, an MBA won't have a PhD-level understanding of chemistry or chemical engineering, but that doesn't mean they can't have a detailed understanding of industrial gases and all the things they're useful for.
I'll make a larger point that this isn't just about MBAs. What I'm saying applies to people of any educational background: business, law, engineering, history, and other liberal arts.
Secondly, you do not need to be from an industry or type of business to succeed in or disrupt that industry. We have countless examples to prove this. Ray Kroc had never managed a restaurant when he bought and transformed McDonald's. Travis Kalanick did not have experience in the taxi industry (nor was he a trained programmer) when he shattered it with Uber. Elon Musk had never built or designed a rocket when he founded SpaceX. Airgas (a major gas supplier now owned by Air Liquide) was founded by a lawyer with no experience in industrial gases. Eli Broad was an accountant before he founded one of America's largest home builders. I could go on. Loyd Blankfein of Goldman Sachs has degrees in history and law, not business or finance. People with intelligence, common sense, and willingness to learn about an industry can often be successful in a type of business they lack experience in. It also helps if they can hire/work with and learn from people who are more experienced. But lacking background is not generally disqualifying. Failure to learn, think, and be coachable is.
My experience is that engineers harbor resentment towards people they perceive as business types. I'm an engineer and I know because I thought this way all the way through college. I clung to my sense of expertise and bristled at perceived trespassers from lesser majors. However, at some point you realize that it's not true and your expertise is only marginally special. Intelligent people of any background with a willingness to learn can figure out the basics of engineering/manufacturing and be useful in various capacities at an engineering/tech company.
MBAs are valuable degrees economically and virtually worthless technically.
There's no reason why MBAs have to be the sole avenue for picking up management skills. They might be a good way to obtain connections and open up new doors, though.
For the record I do not believe MBAs are taught whole a whole lot. However, I do believe people who happen to have MBAs can be valuable by virtue of character traits that extend beyond their MBA education.
Also, getting an MBA is by no means the "sole" avenue for picking up management. I don't think many companies operate that way despite the perception in this thread that they do.