Tort law is in no way a substitute for proper regulation. For example: A company has a tailing pond on private property that leaches toxins into the water. People nearby get sick. Maybe the people can't figure out that the tailing pond is responsible. Even if they do figure it out, they then need to go to court to prove that the tailing pond made them sick. The company says, "well maybe smoking made you sick, or drinking" or any other number of excuses they can come up with.
At that point the onus is on sick people to prove the company hurt them. There is a good chance that a company with a huge legal team can squirm their way out of it. Even if they are found guilty, it could take years for any lawsuits to go through. The company can continue poisoning people the whole time. By the time there are any consequences to their actions much more harm will be done.
A government can look at this and say, poisoning the water is illegal. They don't need to prove that poison is directly responsible for harming people in order to act. There are simply too many ways for big companies with big legal teams to get away with things. If not properly sealing the tailing pond is illegal, then it is alot easier to make sure the company doesn't poison anyone. The government is able to make sure there are rules in place to prevent the poisoning before it happens, making it much less likely to occur. And if it does occur, they have the power to step in and force the company to comply in a way that tort law never can. They can also act alot faster than the courts.