Some MBAs are dumbasses. Some are brilliant business people. Some of them actually have tech skills and have been writing software longer than you’ve been alive. This is true for many degrees.
I don’t know how some of the anti-MBA commenters think it works: A smart software engineer goes off to business school, gets an MBA in addition to his undergrad technical degree/experience, and now… what? He’s somehow dumber? How does that work? Only on HN.
Now, if you already had relevant experience, then went and took the MBA course, and were able to identify when to lean on which, great! But, of course, part of that education is telling you that you don't NEED that experience in the first place, and if it and MBA principles disagreed, you should rely on the MBA principles.
So, if you took the course truly to heart, then, well, yes, you would be somewhat "dumber", so long as you define that as "unable to make correct decisions."
There was no expectation of being "air dropped" into an industry, and in fact, industry recruiters looked for candidates who already had prior experience when picking students for interviews and hiring. The students who had no relevant experience for the industry they were recruiting for (e.g. ex-Peace Corps or mgmt consultant looking to transition to tech or industry in general) were the ones who struggled to find roles. Your assumptions about what an MBA education entails are incredibly far off the mark.
I'm reminded of reading about a Lisp machine company that ran into the ground because it was managed by techies. Their tech may have been great but their marketing and business skills were very arguably what killed the company.