What I read was slightly different. I believe he proposed to fine Apple (or any other company) $1200 for each device sold that didn’t meet their backdoor requirements.
That is equivalent to a prohibition economically. They tax them out of existence. How does this accomplish what they want. The criminal who wants to hide his nefarious activities can still buy a very expensive device that is undecipherable which the law enforcement agencies and even the manufacturer could not break into. It merely costs him a lot more to safely be a criminal. How absurd.