How would I argue that regulation of business is bad for the public?
To argue this, you must say that the market is the most efficient way to give us the consumer goods that we need and the jobs that allow us to buy those goods.
You can argue this by saying that businesses are harmed by regulations. They have to spend extra time and money complying with the regulations. When they do this, they can put fewer resources towards producing goods. When they produce fewer goods, we pay higher prices for their goods. When they produce fewer goods, fewer people are hired to make those goods. Both of these are bad for the public as a whole.
So, to make this argument you need to say that less regulation would lead to more business activity. More business activity would give us more products for cheaper and would give us more jobs as well.