Why should employees have an opt-out of the minimum wage (.pdf)? What does it achieve?
It just makes the vulnerable even more vulnerable by enabling unscrupulous employers to put pressure on an employee to waiver the’re right to it.
You can say there will be sanctions for employers that will do this, just as there are employers that don’t play by the rules already. This just gives them something else to fuck people with and, realisticaly, if people are getting fucked over now when everyone has to be paid a certain amount this is not going to make the system more robust, is it?