In California the median household income is $67,458, and the median house sales price is $405,000, or about 6x median income.
So no, it is not actually true that the lower housing prices in flyover states are offset by lower incomes. Housing in California is proportionally twice as expensive as it is in Ohio.
http://dailycaller.com/2015/10/25/1-in-2-working-americans-m...
If you look at per capita income instead of household, Ohio gives $135,500/$26,937 ~= 5, and California gives $405,000/$30,441 = 13 By that standard, California is 2.6 times more expensive instead of only 2.
But you'd need to earn 159k per year in San Francisco to match the spending power of that $55k in St. Louis. And even that wouldn't be nearly enough to reach parity in home purchasing. Housing is 790% more expensive in San Francisco!
I get that it's fun to joke about flyover country, but the numbers are what they are. People simply are not struggling to move out of the house in St. Louis in the same way that they are in the Bay Area, for example.
Which is to say, once again, that there must be other factors at play.
http://www.bestplaces.net/cost-of-living/st.-louis-mo/san-fr...
"Cheap" housing only goes so far when your employment is 30 hours per week at the local Walmart for $9/hour. You're trying to pretend this is some "coastal" phenomenon, but you can't get there from here - you can't get the number of young people who have left the nest down from 60+% to just barely over 30% without it involving the entire country.
Young people in middle America can't afford to move out either.