The idea
I think the law was passed, restricting DIYers to just wiring a plug or similar. It was based on the fact that deaths had occured by electricution. Some of those deaths were professionals, and this was not made known, so it is not really a fair law.
Why is it important?
A lot of people just cannot afford to pay high tradesmens prices. This law will hit the poorest in our society once again. The rich are rarely DIY enthusiasts.
Very good idea.