What exiting opportunities are you talking about? How someone was not sent to France or Asia to represent the company one works at but now can with the blessing of a piece of paper which really only proves one got in but not much more beyond that? I was treated like shit in interviews when I tried to transition from a support role to a trading function about 17 years ago just because my college was not all that great. Then I instead went for an advanced quant program at Carnegie Mellon and voila, I was suddenly flown in via business class and accommodated in top hotels thousands of miles from the US just to fly in for the final round of interviews towards my conclusion of grad school. It was surreal and outright disgusting. I was offered several trading positions right out of grad school and the firms truly competed for my signature. I hardly ever applied a single thing I learned at school at the job. You tell me how valuable that grad school degree really was other than open doors.
You've been on Wall Street for a long time. You know it's competitive and generally firms look for people who exhibit intelligence and competitiveness in their previous experience. We had a guy who went to a small third tier school. However we was an all star athlete and graduated at the top of his class in three years (both hs and college). CMU shows competitiveness and intelligence. If you went to ecole poly technique you would have shown that. but you didn't so you had to show it another way. That's how meritocracies work. Those who exhibit the most potential, get the most opportunities.
So what can an MBA program do for you? It gives you access to ambitious, intelligent people who have different and interesting ideas. my wife went to a top MBA program. A lot of her friends are doing really interesting things: ceos of disruptive companies, partners at consulting firms, innovative philanthropy. None of whom she would have exposure to on the trading floor. If you are myopically focused on exotics derivatives trading then an MBA isn't for you.