For example, in my MBA at the University of Colorado (CU), for:
#1 What you actually learn: there are a ton of startup/entrepreneurship classes: Startup Feasibility, Business Plan, Startup Execution, Entrepreneurial Projects, Entrepreneurial Finance, Entrepreneurial Marketing, just to name a few.
#2 In state tuition turns out to be around $25k/year. That's $50k total, which is 1/3 the cost stated (granted, CU is no ivy league).
#3 Making up what people actually do (agreeing to jobs for an additional +2 years) doesn't necessarily mean it's what everyone does.
#4 The right network. Boulder is the home of TechStars, The Unreasonable Institute, as well as a ton of other startups. It has a huge tech scene, outdoor industry, natural+organics, and green energy scene- all of which have a host of startups.
#5 Just because other people don't start businesses with their MBAs doesn't mean you can't.
I understand it's common for a lot of places like HN to dog on MBAs, but as an engineer who finished my MBA (but is staying an engineer), I think people underestimate some of the value of getting an MBA. Granted, it really depends on where you go, but there is such a thing as a good MBA.