A small fraction of engineers have compensation that high, certainly not enough to really impact house prices that dramatically.
1. (older residents) Capital gain taxes. If your house is up by $1.5M, selling incurs capital gains on $1M ($500k excluded). That's nearly $300k (20% of value) in capital gains taxes owed -- a huge hit to move to a cheaper place. And if you stay in place and die? Your heirs don't have to pay cap gains at all.
2. (newer) Mortgage tax deductability grandfathering. New buyers have $750k mortgage interest be deductible; old buyers get $1M. Guess you aren't moving until you bought recently!
Looking at the sold houses in my neighborhood and the families that move in: a lot.