If you know that structuring is illegal and you tell -y-o-u-r- -e-m-p-l-o-y-e-e-s- your bank[2] that you are doing it to evade reporting, you admitted a crime to a witness. It doesn't matter what you are doing with the money after it is withdrawn. If he was using the money for money laundering or other illicit business, that is a separate crime from the one described in the article.
Dennis Hastert, former Congressional House Speaker, was convicted of the same charge[1] when an investigation into his (alleged) extortion/hush money used the same tactic to avoid financial reporting. AFAIK, he wasn't actually convicted of child molestation or statutory rape, but was convicted of the money laundering-related crime (because that was easier to prove).
Whether avoiding financial reporting is a reasonable statute is beside the point, but perhaps what you were commenting on.
The way I look at it, it's like a seat-belt law. It's only reasonably enforceable after you've already been pulled over for some other moving violation.
It seems to be in-line with most of the federal code which is designed to give federal prosecutors outsized leverage in plea negotiations. The more charges and the more years of prison they can throw at a defendant, the better the odds they will come away with a conviction. Sadly, this also leads to a lot of largely innocent people taking plea deals to avoid getting railroaded by vindictive prosecutors and less-than-rational juries.
[1] http://www.motherjones.com/politics/2016/04/dennis-hastert-s...
[2] https://www.justice.gov/usao-wdmo/pr/springfield-business-ow...