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.
Even though it did seem to end up working out pretty well for Elwar, I had thought that it was a bit of a step too far.. but of course, none of us know the exact circumstances, and it did seem that Elwar had gotten into a mode (at that time) that he was working on being more mobile anyhow, so sometimes there might not be any kind of reason to stay in one place merely for owning a home there.. and surely, circumstances of job and family could vary from person to person, too.