This is an opionic quiestion. to some people, it is because they dont want to be aroound people who lie or who are crazy and weird.
Maybe because of the temperature it was at night was the same as it was in the morning? :))
It would only be wise to assume a long term context in any business relation when operating in this type of culture. Not communicating inside the context which has been built will surely confuse and likely insult the other party.