I'd speculate that the certification of hours might be an effort to deny unemployment benefits. The company can fire you for cause and claim that you lied about your hours. If everyone breaks some minor rule all of the time, then prosecution and punishment becomes entirely discretionary, used only when furthering the goals of the authority.
I'm not sure if this theory would actually prevail in an unemployment hearing - it varies significantly by state - but the business loses nothing by trying.
The business stands to lose something by trying this: when I learn that they knowingly entrap their own employees in this manner, I will refuse to work with them. I'm sure I'm not alone. Given the cluelessness of many companies' recruitment, they may very well not realize this, but they will in aggregate lose out on some portion of viable talent.
If a terminated employee can prove the sanctions are being applied arbitrarily that's totally grounds for wrongful termination.
But who knows, the court system is so in the pocket of employers in stuff like this and it's so expensive to litigate in the first place it never really happens unless you've got a huge organization with deep pockets.
I'm not sure if this theory would actually prevail in an unemployment hearing - it varies significantly by state - but the business loses nothing by trying.