Yeah, I can't tell exactly what's on his CP (what are those white things?), but it looks like someone just didn't want to spend the money on a flight stick? Damn shame too, because I like the artwork on that.
I wonder if the builder just decided to get creative with controls maybe? I downloaded Ikari Warriors on my Mame cab just to try it out, using the far left and far right buttons to rotate and the center buttons to shoot/grenade, but it sucked. I tried playing Tron on a friend's bartop with modified controls like that, and it was garbage.