I understand not wanting to count a shoot-down but why not count MH370? For all we know there was a safety issue with that aircraft that caused the crash.
After almost a decade of investigation the preponderance of evidence points to murder/suicide by the pilot. A safety issue is highly unlikely.
This is a very USA/western-centric perspective. No SE Asia reporting is stating this.
Isn't that because suicide is a taboo subject in many countries? This was at least the case for EgyptAir Flight 990 and SilkAir Flight 185, and IIRC people expressed the same thing about Malaysian culture.
What do they say?
Why? What are the alternatives?
As I recall, there's a fair amount of circumstantial evidence at this point to suggest pilot suicide as the most likely cause.
We basically know that it was suicide at this point.