I still don't know what point you are trying to make or refute.
If you asking why I think it is completely unrealistic to expect a 50% decline on a short timeline, there are tons of reasons. You have to ask why housing prices doubled, and ask how easy or likely those underlying conditions are to reverse.
1) First, US GDP/capita went up by 60% in those 11 years.[1]
2) Similarly, US inflation in those 11 years was 40% [2]
3) US urban population increased by 25 million in those 11 years [3]
4) Construction costs/sqft are up about 90% in those 11 years [4]
5) More generally, Most Americans have 30 year fixed rate mortgages. This means they can and will avoid selling at a loss, so prices are sticky.
These are all factors without "quick fixes". Slow change can happen, but the fundamentals are sticky. If my house burnt down, it would cost $1M in materials and labor to replace.
https://fred.stlouisfed.org/series/A939RC0Q052SBEA
https://www.usinflationcalculator.com/
https://www.statista.com/statistics/985183/size-urban-rural-...
https://www.mortenson.com/cost-index