The best squat I lived in was a small two-story house owned by a nearby hospital. There was a whole row of them, none of them for rent, and just a few still occupied by owners. The hospital DID NOT CARE what happened to those houses, they were owned purely for the real estate. Some of them had burned down, and the blocks weren't even cleared. As it turned out, a new hospital was built elsewhere instead of the planned extension of that old hospital. As well as improving the house (for my own benefit) I was also a good neighbor for the old couple next door. Previously skinheads and bikies had lived in 'my' squat.
So in that case, was I being a bad criminal? When a house is being kept just for the land it stands on, isn't it irrelevant whether squatters damage it or improve it?
Another squat I lived in had no toilet (it had been destroyed and the hole plugged with concrete.) Fortunately there was a train station nearby, and a large garden for when I just had to pee. No power or gas either, though the water was still connected. I didn't know at the time whether the owner did the damage, or bad squatters, though the further effort involved in blocking up the sewer strongly suggested it was the owner. One day I came 'home' and bulldozers were at work destroying the building, and unfortunately they'd finished with the room where I had my stuff hidden behind a false wall. Maybe the workers would have put it out on the street if they were aware of it, or maybe they would have told me tough luck. I'm not complaining: I knew the risk when I moved in.
Again, if the owner firmly intends to demolish the house some day, why shouldn't squatters be allowed to live there if they're not criminals in some other way or making life hard for their neighbors? Full time squatters displace transient squatters, and the latter is more likely to light a fire in the living room or take a dump on the carpet.