Earlier quoted context omitted.
A much better take to look at that data is this: http://www.vox.com/2015/1/22/7871947/oxfam-wealth-statistic It's the same as to compare someone on absolute salary of $100k in Silicon Valley vs $50k in Estonia, forgetting that the latter can provide a luxurious lifestyle with tons of money to spend, while former can mean being barely break-even.
Median income in San Jose is $80k, so 50% of all households make less than that. $100k does not mean you're barely capable of breaking even. For any reasonable amount of income, it is possible to spend in such a way that you're barely breaking even, of course. But this whole meme of six figures is hard to keep afloat with is the worst kind of cringe-worthy "Oh poor well-paid me." My wife works at Habitat for Humanity…
There are basically 4 socioeconomic classes in modern society: the disposessed, the working poor, the middle class and the wealthy class. You can split hairs and make different cuts, but if you follow this model.
* The disposessed is the people that fell through the cracks. They are struggling to survive usually for multiple issues that are holding them back, even if they have incomes. In a healthy society they should be a small minority.
* The working poor is the people that manage to make ends meet, but are one unexpected big expense away from financial disaster. Unlike the dispossesed their main problem is that the jobs they are qualified to hold do not pay enough, so they may do everything right and still land in trouble.
* The middle class is people that is financially relaxed, even if not rich. They can afford luxuries, and are the prefered target market for many business both because there are many of them and because they have disposable incomes.
* The wealthy run the show. They are not relevant to this dicussion.
The point about "median income" rethoric is that Americans assume the middle class is always 50% or more of the population. So, by definition, median income == middle class. This is not the standard way of things around the world or through American history. Instead, there was an historic anomaly after WWII, when all the other industrial economies were blown up during the war and Americans enjoyed the advantage of being isolated enough to keep their infrastructure mostly intact. Every Risk player knows how this go.
This allowed the American economy to grow faster than population during the second half of 20th century, so most people could aspire to join the middle class, and the upper tiers of middle class could aspire to join the whealty class.
Arguably, the oversupply of money in the Bay Area is reverting this trend. This is what happened to Spain in the 17th and 18th century. The country itself got rich because of all the resources they extracted from their colonies in the Americas, but the rest of their economy did not grow as fast.
The result is that everyone that was not connected to the gravy train from overseas was, in effect, poor... even if they had enough money on their pockets to qualify as well to do in places like Central Europe that did not have colonies of their own. The well-off German farmer had access to cheap food, shelter, craft goods and the occasional specialized service that were simply not available to the average Spaniard lackey, because those last were priced out of the market by the soldiers and the customs officers.
Now the colonies are in the cloud, and software developers are the workers that help bring the value produced there into the realm of physical reality.