People with “aviation expertise” can’t decide where to set the standards, because that decision is a political one, not a technical one. People with technical expertise can provide input to the decision, in the form of advice about comparative risks and objective data, but technical experts are not qualified to make the ultimate decision as to where the standards are set.
Get it?
Politicians with no aviation expertise would be even less qualified to make the decision, wouldn't they? Surely that's why the Act provides for a regulatory body to make rules pertaining to aviation.