1) Please do not go thinking that $7.5B in VC deals * 46% are seed/series A = ~$3.2B in seed money. The bulk of that money is skewed upward to the other 54%. If we assume the average size of a deal in the 46% is around $300k (since series A rounds are more and seed rounds are less), then you get about a $100M market for early-stage investments.
2) The section titled "Average Salaries in the Valley" is actually a graph of median salaries. It worries me that the infographic uses the terms "average" and "median" interchangeably, though at least they chose the better statistic for the chart. They also make no mention of stock options or equity that you get with those salaries, so it's not really a total compensation number.
3) The buying power part is completely off base. Having lived in San Diego for 3 years before moving to Palo Alto, I can definitely say I would rather make $92k here than $59k in SD. I imagine they are including all of San Diego County, which is huge and has vast differences in quality of life. Compare that to Silicon Valley, which is generally nice everywhere you go. If you're living in a comparable part of San Diego, I would imagine you are looking at no more than a 10% difference, tops.
4) The cost of housing is also ludicrous. Either the average is getting skewed because of some super expensive listings or they are simply talking about the average price of a lease. I just moved out of a 5 bedroom house in Palo Alto which cost $3300/mo. I was paying $650/mo for my room, which is about $150 less than what I was paying to live in UTC in San Diego and about half the cost of a beach-front apartment rental there.
In summary, there's lies, damned lies, and statistics. Just move here. You'll be glad you did.