IOW, inept management in everything they do, not just this incident. That's how they shot down an aircraft by accident years ago and obviously they didn't consider airspace control and management as part the problem that led to that incident.
The Separatists, OTOH, fired on a target they could clearly see, was flying higher than most Ukraine military flights, was on a path civilian airlines had regularly used even if most were not still using that route, and didn't bother to positively identify the aircraft before they locked it up and launched. That's arguably criminal negligence rather than just poor practices. It's something a reasonable individual could be expected to consider.
There's a big difference between systemic negligence the criminal negligence of the shooters.
Arguing that Ukraine doing everything right would have kept this from happening doesn't absolve the shooters of criminal negligence particularly since the contributory negligence was not in and of itself a factor in the lethality of the result but only something that increased the exposure of the aircraft to potentially lethal situations.
Increasing the risk of a potentially lethal encounter is a far cry from the shooters intentionally unleashing something designed and built specifically to achieve a lethal result.
JMHO
No one here has said the separatists should not be held responsible. Worse I have seen was partly responsible. However to act as if Putin personally did this himself is kinda crazy. When you have Cossacks running around in an area, anything is possible. They are historically known for being uncontrollable with a hair trigger. From the reports we have seen, they thought it was a Ukrainian military plane and when they found out it was not, they said oh well. Should not be flying into a war zone. Terrorists intentionally target civilians. So to call them terrorist is also kinda crazy. They did not celebrate after they discovered it was civilian as Islamic terrorists would.