The article goes on to give examples where this has been legally determined to be a significant area - over 5 hectares (12 acres) around a property ... for people like me who don't fully understand areas in this context, that would be a square of 220m (720 feet) to a side.
You are allowed to fence this area off, or take other security measures.
And ultimately - its not hugely different to the current situation. If I intend to commit a crime against you, is adding a trespass going to dissuade me?
And that's ok! Not everyone has to own acres of undeveloped land!
I think it's appropriate that some kinds of ownership are as much a responsibility as a privilege, similar to how not everyone is prepared to be responsible for river or stream running through their property.
For a somewhat tortured metaphor, there are seats on planes that give extra leg room, as long as you're willing and able to help others in the case of an emergency. You get the benefit of the extra leg room, but you get the responsibility of helping others in an emergency. And that seems like a fair balance!
Someone malicious doesn't care about laws anyway. If they get caught today, couldn't they could just deny that they were there? I don't understand what would change in that case.