I chose to go back for an MBA after 8+ years of a wonderful career because I knew there were significant holes in my knowledge that I wanted to address while simultaneously using it as a platform from which I could start a company. Yes, the alumni connections are wonderful and the school name does carry some weight in certain circles, but more than anything I love learning from faculty who are some of the great entrepreneurial thought leaders of our time and passionate students who genuinely want to create businesses with lasting value.
Of course it's crazy expensive and it's not a choice you make lightly but for me personally, it was the best possible way to become an entrepreneur. (The school actually gave us some funding/grants, allowed us to incubate on site, etc. Super supportive.)
Oh and I am considering applying to Y-Combinator/TechStars when I graduate because while I'll have a solid business foundation, there is still tons I need to learn about entrepreneurship.