"After all, what is your host's purpose in having a party? Surely not for you to enjoy yourself; if that were their sole purpose, they'd have simply sent champagne and women over to your place by taxi"

The quote recommends that the function of a party thrown by someone else is not necessarily for the satisfaction of the visitor, but rather for the host to show off their house, belongings, or social standing. The host might not care whether the visitor is having fun or not, and the concept is that if they did, they could have simply sent out over some presents rather of hosting a complete party.