Do I? What percentage of VC money goes to people living in areas where $50k would be a good year's salary? It's practically 0. YCombinator won't even invest in companies that won't move to the valley. http://www.ycombinator.com/faq/#q21
However, most people are just commenting that you're wrong about 50k/year not being livable for most of the country. Almost everywhere, including places like Seattle, 50k/year is what half the households make, so works for an individual salary. It's the vast minority where 50k/year isnt livable for a single person.
Of course, that's also partly what people are calling out elsewhere in the thread: high VC spending close to them is about social connections rather than what makes economic sense.
I expect that if you had the capital, you could eat most VC's lunch by just spending everywhere but those hyper expensive areas.