ARe you against speed limits on highways? They are set at some arbitrary number. Your reasoning is: "if 65mph is safer, why not 10mph?"
Wow. That's a dumb analogy. Do you want to take it back, or do you want me to tear it apart?
What is so sacred about the price of labor? Would you advocate price controls for all things or are you just selective for your own self interest?
A speed limit is not a price. A wage is. That is a crucial difference. Basic economic theory, confirmed by extensive empirical analysis, states that arbitrarily set prices create shortages and/or surpluses.
Specifically in this case, arbitarily high wages create unemployment. If businessmen are forced to pay more for certain workers, they will make do with fewer of them. Other businessmen who would have expanded and hired more will now choose not to do so. An arbitrary wage floor will benefit some workers with higher pay, but they also hurt others by denying them employment. This has been confrimed by countless empirical studies.
How can a policy that denies wokers the ability to secure a job be considered just?