Questions were raised as to why Malaysia Airlines had continued to fly over such a volatile region, where separatists were known to be shooting at aircraft. Qantas, the Australian carrier, said it had been steering clear of the area by 400 nautical miles for several months. Malaysia Airlines said that after the crash it immediately altered its flight paths, while other airlines either did likewise or emphasised they had already been taking alternative routes.
"With immediate effect, all European flights operated by Malaysia Airlines will be taking alternative routes avoiding the usual route," said a statement from the airline. It added: "The usual flight route was earlier declared safe by the International Civil Aviation Organisation. International Air Transportation Association has stated that the airspace the aircraft was traversing was not subject to restrictions."
It obviously didn't consider the use of dedicated anti-aircraft weapons. But even primitive shoulder-launched MANPADS like the original Strela-2 have been recorded striking easy targets over 24,000 ft ( a Hunter over Oman in the 1970s ).
http://flightaware.com/live/flight/MAS17/history/20140717/10...
http://graphics8.nytimes.com/newsgraphics/2014/07/17/mh17/4f...
It was a route taken by SQ ,KL and others
EDIT: oops sorry I haven't realized the labels aren't part of the image, I took it from here
http://www.nytimes.com/interactive/2014/07/17/world/europe/m...
Might be weather conditions this particular day pushing all the planes north east. I have zero idea about air traffic, is there an airport doing flight control for the region that would reroute all the planes over the effing war zone because of some rain clouds?
Perhaps I can point you to the link in the comment to which you've replied which plots the courses of flights of Malaysian and other airlines from the past weeks so that you can check?!