Diego Garcia IS A US MILITARY BASE.
It is unthinkable for any US military base to have less than 4 fighter jets at any time (2 to lift off in case of some urgent event and 2 to stay on base to defend it). As for the maximum just have a look at the photos it could be hundreds.
Diego Garcia is not a Hotel or some sort of leisure place.
Just like Dhekelia base in Cyprus civilians can go there and have fish and chips and walk around and think of " what a peaceful place" until they realize they can't even get close to sensitive areas. The truth is -and we all know it- Dhekelia and more so Episkopi are nothing but peaceful places.
The hypothesis that MH370 was shot down because it became a threat to Diego Garcia cannot be ruled out by assuming that a)Diego Garcia is "usually empty" from fighter jets or b)Militants would need to ask permission from the Pentagon to shoot it down or c) they had to show mercy to an innocent civilian plane or d)the Americans would go out and admit and and tell the reasons why they did it or whatever.
Of course all these hypotheses or theories could be totally useless if the MH370 case was one of the standard cases where we had either a)Mechanical/Electrical failure or b) wrong handling of the problem by the pilots or both at the same time or c)Hijack or d)shot down by accident
Malaysia itself admitted it was a criminal act.So far absolutely no indication for a Hijack. So what's left other than a totally NEW CASE?
My new theory says it could be robbery of extremely valued cargo. And it happened while the plane was over land.