Median household income in Irvine is 83K according to the Census Bureau. Such households cannot afford a 600K home, even at 5 percent rates. Get your facts straight cashman.
Comparing median income to median priced homes is a flawed argument. 50% of people in OC make more than 83K. What is the home ownership rate ? Suppose it is 60%.
Therefore, it is not the median income family buying the median income house. The median income family is in the bottom 17% of homebuyers (assuming income proportional to price).
It would be more correct to compare say the 70-75th percentile income to the median price, if you want to take statistics and make an appropriate example out of them.