Squatting is good in my opinion, property rights are overly favorable to property owners while neglecting the needs of the property-less. The world is not like a game of Monopoly where we all start out with the same potential and resources and succeed or fail through a combination of look and good or bad decision-making.
I think it's worth remembering that the US mores about property as enshrined the Constitution were a) meant to protect against landed aristocrats' forcible expansions of their estate, and b) codified at a time when the first Americans had colonized one relatively small corner of a continent that seemed vast beyond the imagination, and the acme of mechanization/industrial production was the water wheel.