The intent is not to fool anyone, but to provide a face-saving interpretation when socializing falls flat. You didn't stop in for a conversation that might or

The intent is not to fool anyone, but to provide a face-saving interpretation when socializing falls flat. You didn't stop in for a conversation that might or might not go well; you stopped in for a drink, and that worked. Having some other activity involved (having a drink or otherwise) lowers the stakes when interacting with new people.