Feels more like a full on simulation to me, what with my Rift, TM Warthog  and JetSeat. Trying to simulate something just for fun is a bit different from playing a game, imo.   
It's all to do with your approach. DCS on a monitor, using mouse and KB, with the TV on in the background, in a well lite room, while chatting to the wife, yeah that's gaming.