So, how do you punish everyone fairly? By fining the company for a large amount of money. Shareholders lose their value, employees don't get their raise, and execs won't get their bonus, there is a good chance they get fired too. Companies are for profit, it is even more true for public companies, for which profit is their duty to their shareholders. So hit where it hurts, that is profits.
As for jailing CEOs, what will it bring? Don't forget that a CEO is just an employee, hired by the directors to maximize profits for the shareholders. If the entire company is corrupt, everyone will be more than happy to hire scapegoat CEOs if it can serve their interests. Jailing them will solve nothing, it may even be counter productive as those who are most likely to get that job are people who are ready to risk prison to win big, a crime lord profile.
There are still reasons to jail the CEO, but only if he personally deceived the rest of the company and shareholders, but that is effectively the same as stealing from the company.