Why do you need to "prevent companies from being overcautious?" It's their money they're spending, it's their customer relationships they're putting at risk, it's their liability they're increasing by having someone with multiple DUI convictions driving around the work truck.
Criminal history is not a protected class (nor should it be), there's nothing wrong with a company saying it doesn't want to hire people with criminal histories in the recent past for certain jobs, or any job.
While your words imply that you have an ideological opposition to telling businesses what to do, and that external effects need to be ignored. Why do businesses have the right to do things harmful to society so that they can make money?
Businesses get told what to do all the time, that's not necessarily a bad thing. But businesses have a right to choose how they spend their money and who their employees are.
Criminal history is not a protected class (nor should it be), there's nothing wrong with a company saying it doesn't want to hire people with criminal histories in the recent past for certain jobs, or any job.