The whole idea of forming a business entity is to limit the liability of its principals. This is an important incentive to make people go into business without risking their home and whatnot. Let's not throw out the baby with the bathwater.
I think the limited liability is for debts to creditors and shareholders, rather than limited liability against criminal or other behaviour.
Maybe I’m wrong, but as I understand it, Australian law treats a corporation as a person and the directors are answerable if the corporation breaks the law.
The real problem (as I see it) is that a company the size of Optus can afford to defend their behaviour for so long that enforcement itself becomes a burden. The closer you get to the CEO and board, the more they will spend shareholders money defending themselves.
When you really think about it, that is a VERY scary thing.
Quite literally it goes:
"If I do this illegal thing myself, I'll get in lots of legal trouble."
"If I form a company and do the illegal thing, I'm safe."
Actions without proportional consequences were never going to lead to anywhere but destruction. Folk psychology told us that was likely (however much virtual-economists feigned ignorance). Empirical reality has confirmed it.