Don't get me wrong, it's rude to not acknowledge someone doing something positive for you, but I just see it as, glad I'm not them.
This is what I imagine of people who do what you mention-
after a Sunday family dinner out, they go home, sit on the couch together, whack the tv on and then...
Just feel good about yourself. Be happy that you're the sort of person who would do that for another. If I do a good deed, I don't care what I get back in response, I'm just happy to be ab]le to help. After all, there's no gift like giving.