As a 200,000+ mile flyer, I sympathize, but as the other posters have said, it is a right to recline your seat as you wish. Why didn't you ask the person to move their seat forward during the meal service? To avoid this in the future, get a bulkhead or seat in the exit row, where the row in front may have limited recline. A propped magazine if you are in the aisle is an obstacle to deal with for your whole row. I wish that short duration flights, say less than an hour, most pax should not inconvenience their fellow pax by reclining the seat, but I tend to get the one person in the cabin who wants to do so sitting in front of me. It forces me to in turn recline my seat. On long flights, it is expected that most pax will recline their seats. Best bet is to fly up front on a long flight and not worry about it.
-outoftown