Its a pretty normal part of the cycle and yes some properties sell but usually they are by vendors who have pressing reasons to sell such as divorce, death, financing a business, going overseas etc,
Seen this before and will probably sell a house in Auckland early next year at whatever the market dictates. Fed up with being unable to evict tenants that frighten neighbours, too many restrictions on good and competent long term landlords.
People have an expectation of what their house is worth, Joe's house down the road sold for $1.2m
so ours must be worth $1.4m. They put it on the market but only get offers of $1m so they decide to stay, pull the house off the market, add on a basement and pool and over capitalise the place.
Eventually they get too old, have to go into a retirement home and sell at the real market price which will have gone up on the upwards side of the cycle.