Cat calling...

Tried explaining to my cat the other day that she belongs to my family and hence cannot have a life of her own. What brought on this conversation was her coming home at all odd hours of the night, dropping by to grace us with her presence at mealtimes, et al. Told her that since we look after her lodging and boarding the least she could do to pay us back would be to occasionally chase and bring down the odd cockroach, rub herself across our legs as a sign of appreciation, or maybe even entertain us by friskily running around the house chasing her tail. But did my heart to heart do any good? Nah, she blinked at me, gave a wide yawn and promptly went back to sleep.
Why do people love cats so much? Can't figure it out...