As for deterrence: it appears as if the SEC successfully deterred Ensign Peak from doing this, right? They hadn't filed properly since 1997, but the enforcement action is just a couple years old.
There's probably a joke in there somewhere about the 13-F process being "securities theater" as compared to the better known IT "security theater" phrase. 13-F is a classic example of "regulation can sometimes be wasteful and inconvenient" therefore anything wasteful or inconvenient can be hand waved away by appeals to "regulation" much like the classic analogy with computer security. See also security theater at airports, plenty of the governmental covid responses, etc.
>Also, the fine is intended to discourage the behavior. If the money obtained by breaking the law minus the fee is still positive
The money saved not renewing your registration on time is roughly the same regardless of what you're driving so that would seem to favor the fixed fine.
The fine should scale with the size of the infraction. If you sticker expires on your car, the infraction is the same severity, no matter the car [0]. Hiding a few million vs. hiding a few billion in taxes is a whole different level.
Also, the fine is intended to discourage the behavior. If the money obtained by breaking the law minus the fee is still positive, there's no incentive to stop breaking the law. $5MM on a fund worth a few billion is very likely to be well within the still profitable area.
[0] I'm not sure about the US, but at least in Germany, an expired sticker actually is a larger infraction for commercial vehicles, especially if you transport people. So even there it's correctly scaling with severity.