An internet search on the phrase "shofar at night" will bring up a variety of halachic discussions on the topic. But this is a question where practical considerations seem ample to provide an answer.
For example, my immediate reply to my friend was, "Because it would wake up the children."
Consider, too, that there is no visible moon on Erev Rosh Hashanah. Until only recently in human history have we had the practical ability to light up the night through non-celestial illumination. I believe this is the reason why services in the Miskon and Temple were daytime affairs, and nighttime gatherings of worshippers were few.
ON THE OTHER HAND
One notable example of nighttime blowing is the story of Gideon, in which his troops blow shofar in the darkness as part of a surprise attack on the enemy camp.
|Gideon: Blowing Shofar at Night|
From a paleo-anthropological point of view, would it not make sense to blow shofar at night, either to scare away the unknown threats lurking in the shadows or to call, like wolves and birds, to announce one's territory.
What's your insight into this?