You people are totally missing the point. You should realize that the 0.05 to 0.08 enforcement isn't aimed at directly preventing issues with people in that range, but rather to further deter people from drinking and driving at all. (Thus reducing the number of people who end driving over 0.08).
Its not a cash cow or a scheme of the MADD lobby

, its aimed at reducing the number of drunk idiots on the road that can end up killing people (unless its a U-turn, thats apparently fine).
That said I think the 24hour/impound rule is pretty dumb, although it would certainly be effective.