There are many cases where alcohol is not present and someone is prosecuted. The problem with your opinion is you don't understand that alcohol related cases are prosecuted more because alcohol related cases occur more. That is similar to blacks whining that there are more blacks in prison than whites even though the reason is because more blacks commit the crimes.
I have my differing opinions on alcohol and speeding because I've experience both first hand. I can't drive straight when I'm incoherent but I can drive just fine going 85 in a 65 as long as other traffic is driving a similar speed or there is no traffic at all. Being coherent behind the wheel is the most important aspect to driving.
"The problem with your opinion is you don't understand that alcohol related cases are prosecuted more because alcohol related cases occur more."
Not at .08, .10 or even .12. They occur more at about .14 and above. The reality is that the alcohol is prosecuted in a "might" cause a crash as well as a "has" caused a crash scenario. While the rest of the negligence is only "sometimes" prosecuted in a "has" caused a crash scenario.
"Being coherent behind the wheel is the most important aspect to driving."
That is what I have been saying. Being coherent also requires paying attention and being prepared for adverse actions by outside influences.