ian w . your theory of little or no interest in an aircraft wandering around the skies might have some validity if the disinterested parties were unaware that an aircraft was missing. 370 was known to be missing at the time it should have contacted vietnam and it is inconceivable that the word did not reach all parts of se asia in a very short time. all surrounding atccs would be on alert for the aircraft on radio and radar. interest would be of a very high order I would say.
I don't know about that. I suspect that when word was passed that 370 had disappeared off radar and wasn't responding to calls - and that there had been no mayday or emergency codes - people started looking for it. But they weren't looking -up- for it, they were looking -down- because the general assumption would have been a crash, not that the plane was out joyriding far from its intended destination. Doubtful if anyone would have noticed a random radar blip and thought "gee, there goes that missing plane!"