If I had an "extra" house, I could have sold it in 2016 too as I was trying to invest as much as I could (within some strict limits), but selling the house where I live-you have to be a bit more adventurous-like the Taihuttu dude (he sold the house when btc was $900, became a nomad with his whole family).
In any case, selling a live-in house to try to gain a bit of leverage is probably beyond most people. I have seen a couple reports like this, but usually it was a second house of a house that was inherited.
Well, it's certainly beyond most people today since house prices are no longer affordable for the vast majority of the population. Being born at the wrong time and to the wrong parents is a common mistake these days.