On the other hand, depositing money is the normal status. Depositing what amounts to large sums over arbitrary periods of time is also normal. Directly to the point, the limit in place is not a restriction, but merely one that triggers mandatory reporting. The limit is very clear and absolute -- though at their discretion banks may report smaller transactions. Structuring is specifically about avoiding that limit and the accompanying questions and reporting.
So how would you rewrite this law to require mandatory reporting, but also not allow structuring? Because it's not apparently trivial how to achieve that goal any better than they did.