Your mistake is to think that regulations are anything other than law and order to ensure civility.
That's exactly what they are, so by your own definition, this IS part of government's job. Just because the particular type of laws are specialized to deal some unique circumstances that don't really exist with individuals doesn't make them any less about maintaining order and civility.
You can poison somebody, maybe a few if you are very good at getting away with it. A corporation can poison millions of people in a day for about a penny each and consider it well worth while, all while shielded by limited liability laws (which to be fair, may actually have some merit and could indeed be as claimed much more good than bad). That's a unique circumstance - so we make specialized laws for that circumstance.
If I have a complaint about regulation it's that it tends to go in the opposite direction of where it should: we shouldn't have less regulation, we should make the punishment for violating existing regulations much, much harsher.
The principle of equality before the law demands that, if a company does anything bad, it's CEO should face the same punishment I would face for doing the same thing - multiplied by the much larger number of victims.
When every CEO who dumps toxic waste in a river gets the same death penalty (or life in prison) I would get if I poisoned you - nobody will dump toxins in a river.
The problem with regulation is that it, all too often, allows the CEO to get away with a fine for crimes that you and I would get a lifetime in prison or even executed for.
That problem however cannot be fixed with deregulation - it can only be fixed by making the punishment for violating regulations much, much harder so it's in line with criminal law.