One of the pins on the original University of Wyoming object course was the Vietnam Veterans' Memorial Monument. A veteran complained about disresprect, and the University nearly banned the whole course. Later they let us back with a redesigned layout (interestingly, because it is seen as a recruiting plus).
Afterwards I apologized to the Veterans. They (all but the one) wanted us to reinstate the monument as a pin. They felt that it was a great way to have more people made aware of it.
A cemetery is a memorial. There's not much point in a memorial if nobody visits it. What would you want for yourself and your descendents? Would you want your descendents to bar people from the vicinity of your headstone because they were playing a game? I wouldn't.
I know we can't do it, because we can't risk offending those who believe that you should behave in a cemetery as you would in a church. As pointed out above, it wasn't always that way. Too bad it is now.