Generally because they prioritize ease of operations over helping customers overcome jetlag. In this particular situation I'd guess the ease of operation comes

Generally because they prioritize ease of operations over helping customers overcome jetlag. In this particular situation I'd guess the ease of operation comes from: * full customers are easier to deal with than hungry customers * Doing meal service early avoids the risk that weather turns rough, making a late meal service hard/impossible. * Crews are fresher earlier in the flight, and so are do a better job and prefer doing meals early. * Waking customers up is extra work for crews, and may not be wanted by passengers.