For the vast majority of people in minimum and low wage jobs, there is no training, no development opportunities and no support to move onwards or upwards. Combine this with poor schooling and a social environment that does not value work, and the end result is that few people with develop beyond a low wage environment.
Thus, the need for protection.
Much low paid work requies skills - eg. bar/restaurant work.
Given the current state of the jobs market - many highly educated people are taking mimimum wage jobs.
There was a recent case of a cimena being opened getting bucket loads of CVs.