Serious question: why else would you go?
Contrary to the unfortunate opinions of many here on HN (I get it, I am a former engineer), there are more good MBAs than bad ones. What I can say with certainty, is that I have never spent time with a smarter, more motivated group of people than I did in B school. That includes my time at NASA and working at couple startups. It's a unique experience, and to me at least, worth the cost even with zero financial return. But if you want to make more after B school, it's easier. Not everyone chooses to.
ymmv