In the parent's example, "shorting" the overpriced neighborhood may never produce a return since overpriced houses can remain overpriced for a very long time (decades).
This is basically saying "it's not overpriced if enough people believe it to be the correct price" which yeah, sure. In that case it's impossible to make money on most overpriced asset classes (other than those you can make yourself).
Seems like they can stay overpriced for as long as there is no better place to put the money.
then it wasn't overpriced no? Overpriced means that you can get it for cheaper.