In reply to scope:
It's been raised before, whether formally at a BMC area meeting or not I'm not sure but there have been military bolts at Great Mis for 10 years at least.
As others have said, there are many reasons they could have for bolting (as you have pointed out, it's not much use for climbing) and also many other ways they could have installed a load-bearing anchor. It's probably just easier and smaller than a great big staple etc.
As far as I remember, Great Mis is their rock. So yes, they can bolt it if they choose. As could climbers if they were the landowner, regardless of the "rules" participants in the sport (usually!) adhere to.
Had they chosen to bolt a whole crag-full of trad routes , then certainly a conversation about military climbing coming into conflict with the climbing community could well be worthwhile.
As it is, if members of the climbing community starts tampering with an anchor the MOD have placed, particularly one that doesn't appear to have a climbing purpose, this will certainly not support good relationships regarding access in the future, on Dartmoor or other MOD-owned land. Please don't remove it...