There is no way to make a stove safe in the face of incorrect usage. I wouldn't be able to judge whether flame interlocks should be mandatory without any statistics about the frequency of this type of accident.
Sure. The risk is low, it just seems unusual given the tendency to wrap everything in five layers of liability reduction features.
It seems society's tolerance for mortal danger depends more on the cause of the risk than its magnitude. I guess the occasional gas accident is one of the acceptable reasons for people to die.