I agree with that, but I don't fully understand who it is that's buying all these homes. 

If it's driven by flight out of NYC, LA, SF, or DC, then it makes sense to me. Selling a home there would give you plenty of money to buy a home in the growing mid-size metros. However, there should be a corresponding decline in the major metro housing markets. 

My other thought, is that people may also be moving out of apartments in cities and into homes.

Undisciplined

econ

Real estate prices are rising: good news - the Fiat pump is working again

TomK

See your point, but whilst many are being priced out, not everyone is.  Those still able to afford it are funding higher prices because demand is still higher than supply, even though lots of us, particularly the younger generations, are priced  out.  The two developments are not mutually exclusive because the housing market is made up of many different segments.  
I kind of agree that house prices should fall on a historical basis, but they are not; Im just trying to reason out why that is.  Could be wrong...