"But the bluster of Silicon Valley, combined with the fact that no one loses and everyone gains"
Except the general population. These tech companies are causing the cost-of-living in the Bay Area to soar. The population of employed, yet homeless, people is growing rapidly. The problem stems from all of the overly-valued tech start-ups that are paying their talent $150k a year, but blue-collar workers are still getting their old wages. As the number of tech workers increase, so does the demand for luxury real-estate and decreasing the amount of affordable housing. Its even gotten to the point where a dual-income family can no longer find affordable housing in the Tenderloin district, an area generally regarded as a complete shit-hole (To use a technical term), even Oakland is slowly becoming too costly for people.