So how does this market crash? This is something I have struggled with for some time. Markets have typically crashed because public investors buy at very high prices and then the market loses faith that the future cash flows of the business will pan out. But IPOs aren't happening like they were. Facebook buying Instagram for $! billion is crazy, but Facebook continues to grow and generate revenue (because of or in spite of Instagram) to exceed investor expectations. If these acquiring companies continue to grow and succeed, then how does the bubble collapse? We have no idea whether Nest can justify the $3.2 billion Google paid for it, we just know that Google continues to beat estimates and the Nest guys continue to afford nice cars.
I also do take exception to the fact that MBAs are all vultures. I am trained as a computer Engineer, practiced as a materials scientist, and got an MBA. Now I am one of those exact vultures you speak of with a startup of my own that I, by the way, believe is going to contribute meaningfully to society.