Why stop there? Why don't the makers of razors, rope, knives, plastic bags, builders of tall buildings etc issue infringements too?
Because you cannot stop someone determined to kill themselves (short of medical restraints etc) and you cannot hold the implement used responsible, which is what the notice is for- it's to prevent liability lawsuits against the council in case someone hurts themselves or gets killed by their own deliberate actions. Which is ridiculous; it's not the builder's fault, and that's blatently obvious, so on what planet do they get off reversing the equasion and fining the victim?!
That poor poor young man, that poor poor family