Not to mention that this would force a culture of attributing blame to individuals which is toxic, encourages people to hide mistakes and when mistakes happen the first thing everyone would scramble to is to find a scapegoat. This is objectively worse for both the company and the shareholders.
The right approach for the government is to appropriately penalize the companies. The right approach for companies is to put in processes that make sure no single person is even in a position to make mistakes like this.
The government isn't penalizing the companies, it's penalizing the shareholders, who are the ones that suffered the inadequate disclosures!
>"Mistakes of this magnitude are often the result of multiple people making mistakes - so blaming a specific person is wrong."
Then either split the fine amongst the responsible parties, or just issue some sort of order that requires changes (such as some sort of audit) without a fine. If you can't find any specific person who did something clearly wrong, it's probably best to avoid blaming 'the company' (which is just a collection of individuals).
The point of the fine is to disincentive the company (and also other companies) from doing the same thing again, unless criminal behavior (i.e. fraud) was involved that’s purely an internal matter for the company (they may fire the people who supposedly did this or do whatever they think is necessary).
If you think it's difficult to figure out who did what wrong, and that the companies are just scapegoating people, then the SEC implementing fines that cause the company to fire people is likely causing unjust firings.