There is certainly no justification for driving while impaired. The regulatory problem is that, like many social issues, the issue has been taken over by extremists. The impairment level has been lowered in the social interests of eliminating the problem to the point where a glass or two of wine and you fail the test. Meanwhile the penalty for driving while impaired has remained the same and is too lenient. You can run over someone and get a few months.
The easy solution is to raise the impairment level to one that indicates actual impairment and increase the penalty. If someone is stopped and fails or refuses the breath test, automatically impounding the vehicle, impose a substantial fine and a jail stay. No arguments.
Continually lowering the level and making the penalty a slap on the wrist. Under the current system there are serious multiple offenders driving around and endangering us all.