Agreed.
Think about it this way. Hypothetical situation: Let's say you are a J-Sec promoter. You want to book an act for a hip-hop show. You have a budget of, say, R1000 to book the act and you know that most active MCs are unlikely to charge less than that.
In other words, because there is a baseline price, you will be more picky about who you book. Because of this, cats will be forced to step their live game up. Any way you look at it, this situation works.
Of course, there's the sheisty promoters who make excuses and won't pay as promised but as X says, there are ways and means.