You can also ask Russia/Rostov why the also only closed the Airspace below FL320 and not complete.
V6158/14 NOTAMN
If Rostov had complete closed so no Flight could have made over the Area.
The next Question: why wanted ATC RND that MH17 change the Route direct to RND? The ATC Reason was: we have three of them. Where?
https://www.youtube.com/watch?v=hh06SqVx_1Q
Everyone knew the Radar Vid. At 13.20.39UTC a Military Object apear on screen at Russian Border. The new flight Route would be go nearby the Object.
https://www.youtube.com/watch?v=766ftKQGqls