"You are right. Child care providers are licensed and there are still bad child care
agencies. But you both neglect to take into account how many persons, both young and old, that martial arts affects."
"A child care provider may only handle 20 people, lets say. How many students, parents, relatives, friends and neighbors can one bad martial arts instructor affect. I think a lot more."
Actually, since there are no doubt _many_ more child care providers than martial arts instructors, it's certain that child care providers affect _far_ more people than martial arts instructors.
In addition, despite the sad tendency for martial arts to be watered down and used as kiddie day care, there are still many martial arts schools that focus on teaching adults, most of whom who are quite capable of quitting and/or suing, and/or alerting the authorities if an unsavory instructor is abusive, violates a contract, engages in fraud, or engages in other illegal or unethical behavior.
There are already laws against, violating contracts, rape, child molestation, and most if not all other terrible acts a bad martial arts instructor might engage in.
The recent New Jersey law would have made it impossible for some important and respected figures in America's martial arts history to have taught. It demaded a level of education some Asian masters (particularly from Southeast Asia) did not have, for example.
As I recall, some proposed legislation has demaded a teacher have a certain belt level before they could teach, though styles that don't use belt ranks, such as Bruce Lee's fighting style, many Filipino and probably most or all Indonesian styles, Muay Thai, Savate, Bando, and others. Such legislation could effectively make such styles illegal.
I see martial arts legislation as likely to give some politically well connected martial arts organization great leverage over the rest of us (How would you like to hear "New federal laws writtten with the help of a major TKD organization makes it mandatory for all martial arts tournaments and sparring to be done by Olympic TKD rules" ?).
I also see such legislation as something that will inevitably continue to water down the arts, as the government makes certain training and techniques illegal, because they are perceived as unusually brutal or dangerous to practice. I have heard that some European country (Norway?) already does this.
I see no good outcome from such leglation, and believe, as I said, that most or all of the behavior such regulation is meant to address is already illegal.