Morality vs. legality of child neglect

Another question:

What is justification for someone to take a neglected child away from the parents? The argument that I heard from Walter Block is that by neglecting or abusing the child, the parents give up their homesteading rights to be the child’s sole caretakers.

But could this argument be used about any other case of ownership? Could I say: “You haven’t changed oil in your car (or, haven’t driven your car) in months, so clearly, you gave up your rights to it” or “You bought this field but just left it empty for seven years, so I can just take it from you”?