While I appreciate where you are coming from, I think your argument is invalid as it uses an invalid example.
Removing lead from fuel was wise as the lead-laced exhaust caused known neurological side-effects. We removed lead from just about everything we could at around the same time in our history (Paint, plastics, etc.)
However, in this case we are ADDING something to our fuel that has questionable (at best) benefits and real known problems. Unlike removing lead, which could be remedied for certain engines with a simple lead additive, I challenge you to regularly and simply remove the Ethanol from your gasoline. (HINT: You can't. It requires a separation apparatus to remove the ethanol before you put it onto your car.) On top of that , purchasing regular unleaded non-ethanol gasoline has become remarkably difficult in many areas.
In NY State, for example, one cannot legally dispense non-ethanol gasoline directly into an automobile fuel tank. it must first be dispensed into a legal fuel canister or into a boat. Thus people with classic cars must go to boat refueling stations with multiple gas cans and fill those up and then take them home before refueling their classic cars. Or plan on lots of repairs.
Once E15 rolls around (and make no mistake, there were and are plans to FORCE rolling out E15 well before your magical percentages are met) Current car owners will also be forced to do the same thing. The "2001" restriction is idiotic. Many BRAND NEW cars (Like my wife's 2012 Toyota Sienna) have a label right on the fuel filler tank "E10 fuel only, not for higher Ethanol content fuels" My 2008 Jeep Liberty has a similar warning in the manual.
On top of all of that, Ethanol fuel is a complete waste of time. It does NOTHING to make the car more efficient or cleaner. Indeed, it actually causes the opposite effect, causing loss of efficiency, thus requiring more fuel to be burnt for any given task, thus INCREASING pollution. It also causes damage to the engine over time, resulting in further loss of efficiency, more expenditures on repairs, and shortened vehicle service life.
There is absolutely nothing good about using Ethanol in our gasoline engines, and it boggles my mind that this kind of stupidity has been allowed to go on for so long. But then I guess when you are dealing with the "religion" of Leftism that is controlling much of the government, irrational things are to be expected.