On a night flight, yes, everyone goes back together and nobody minds. On a two-hour hop at eleven in the morning with the trolley coming, no, and you know it. The question isn't "may I", dear, it's "must I, right now, into someone's coffee".

Night flight, day flight, the seat is the product! I fly Bangalore to SF every quarter and if I'm supposed to sit upright for sixteen hours because a stranger might be tall, the airline should sell me a different seat. They sell recline. I use recline.