We can get this kind of detail on Flight 17 but no one has any earthly idea of even what direction Flight 370 was headed for multiple hours???
I would imagine there’s a great deal more spy satellite activity over that particular part of the world - the eastern Ukraine/Russia border - then there is over the area where MH370 went down.
Well, Flight 17 was not attempting to avoid detection, was over populated areas, was in regular contact with flight control, and would have been on multiple radars, including the BUK’s.
Easier to track over ground where many are keenly interested in what’s moving where, not so much over ocean when nobody cares and pilot is trying to hide.