Hindsight? It was foresight that caused British Air, Air France, Quantas, all United States airlines and many others to avoid the area before the shoot-down. In fact, the majority of flights/airlines have been avoiding the area: "200 to 300 of the daily flights using the route had diverted elsewhere in recent months, leaving about 100 still operating."
Which leaves ~ 99 other pilots that made the same decision with no adverse consequences. So, at worst, it was a 1/100 chance of this happening. Still pretty good odds. (For all the mathemagicians out there, I realize this is a faulty chance prediction, just making an rough observation.)
I have several pilots in my family - grew up around aviation. Pilot error is, of course, a problem. But, there are enough things that get hung on pilots appropriately, that it is against my nature to go looking for more.
In this case, it was not restricted airspace. The pilot followed all the rules. He had a long flight, so fuel consumption was probably a concern. I have no idea what expected weather was further along the route or other issues that might impact the decision. I do know that diverting completely around the Crimean/Ukraine would have posed different risks and costs. All those other airlines you mention are well-capitalized. I suspect Malaysian Airways isn't.
Now, if you're looking for evidence of a conspiracy, that's a whole different kettle of fish.
Edit to add:
Nico Voorbach, president of the European Cockpit Association which represents pilots, said information from the intelligence services will be crucial in deciding whether the aviation authorities erred in not including the Russian-Ukrainian border in the exclusion zone. “I am a KLM pilot and fly over the area. If some intelligence agency did have information about a threat we need to know if it was shared with everybody.
“We will have to wait for the outcome of an accident investigation to see if a mistake was made."
Last edited: