Originally Posted by Steve M

I think the reason for serving immediately is that for a flight that's long enough for 2 or 3 meal services, it would be perceived very negatively to tell passenger "we have fully-stocked galleys, will be serving you 2 (or 3) full meals, and know that some of you are hungry, but we're not going to give you any food right away because some of you may not be at mealtime."