BTW, what is the percentage of population in high paying professions like Medicine, Law and Engineering that are also new first time homebuyers? I doubt it is a large enough percentage to consider that the norm. I would say they are a minority and insufficient. A large percentage of professionals who are experienced enough to earn such a salary are already homeowners and not in the pool to create new demand.
Remember that higher earners also have bigger liabilities like their BMW/Lexus/Mercedes lease, vacations, partying out etc. They are not about to give up their entire lifestyle and live on Ramen noodles to buy one of these overvalued houses even if they would qualify. And yes, their expectations of a house are also that much higher than average so they are not likely to be content buying some small matchbox size crappy condo for half a million dollars.