I have an MBA, but in my defense I also have several years of grad work in theoretical physics and over a decade as senior sysadmin at a large academic compute cluster, so I hope I have enough street cred when I say this.
Don't confuse the body of knowledge, with the kind of people who are attracted to it. Economics, finance, org behavior, strategy are all legitimate domains of knowledge, and can be just as interesting and thought-provoking as theoretical physics.
I got the MBA because a) I like the math-ier parts of business and b) ageism exists in technology, so it's best to add another leg to your stool while you can.
A MBA degree is like a can of car wax. Put wax on a Ferrari, you'll have a shiny race car. Put it on a turd, and at the end you'll still just have a turd. What you take out of a MBA program is largely what you bring into it, and a lot of people don't bring much other than a desire for a promotion with a six-figure salary.