No disrespect but this is what i think. We have a culture so focussed on other's (society's) opinion. A lot of the things we do is based on what others will think about us when we do so and so more than for its own sake. For this restaurant incident, a lot of times people do it so that the other person will think he/she is polite and generous. a lot of times, inviting people home is just formal talk. We do it so the other person wont think negative of us and wont get offended.