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.

shado_op

Demand is the willingness and ability to pay for something. It doesn't really make sense to say demand is high despite an inability to pay.