Aren't we all?

That and there’s the whole liability issue if something happens and it’s found out they were completely aware someone was living there.

It's from the days when records were a lot harder to track down and someone could just die or disappear. After a certain amount of time the state just has to just call it or else the land's ownership is locked up forever. That's why the term of adverse possession is generally lower in the Western "frontier" states than the Eastern states, it was a lot more perilous to stake a claim there and there was a lot of turnover, with poor records. People have successfully adversely possessed abandoned houses in places like Vegas though, and more power to them.

It should be noted that trashing a house, setting fires, shitting in the corner, and inviting 30 of your friends to join you isn't the way this is done. You have to "openly and notoriously" occupy the property, which basically means presenting yourself as the owner. So you live there, keep the place up, and most importantly pay the property taxes. Basically present yourself in such a way that everyone thinks you are the owner.