The regulatory agencies responsible for ensuring compliance with safety and health standards in the USA have a rich history of being cozy with industry (see the fallout after the gulf oil spill, for example). These agencies are overseen by political appointees who are not reliable, and may even oppose the mission of the agency (see the current EPA). Creating an approval channel creates a path to false- positive legality that I don't think should exist. There's a substantive distinction between keeping the whole enterprise strictly verboten and creating an exploitable legal grey area.

I'd prefer if drilling for oil in the gulf were illegal, not legal with regulatory oversite, for example. I don't think a pessimistic outlook on the reliability of federal oversight is unwarranted, given my (admittedly dim) view of how the process has worked in the past.

To be more constructive: I'm up for substantive suggestions for ensuring more transparent and reliable oversite than exists today.

Their criticism wasn't of the law but of the undue influence of lobbyists in the American political system.

Maybe you can’t trust them with novel pathogens designed to kill people.