it's an absolute no-brainer to stick motor tax onto petrol and diesel, so i don't know why the government don't do it. you get taxed based on how much you use your car. some countries even load insurance onto fuel, so you cannot drive uninsured.
the tax on fuel is being loaded these days with tax. close to 100% increase in the 3-4 years i've been buying the stuff. however, you are absolutely right -
possibly though - the lad who represents renault in ireland is a huge fianna fail reacharounder, and renault are going with shitty electric cars (they are renault - if you've ever owned a renault, you would know that electrics are not thier forte. i'm not even sure cars are tbh) and charging stations across the country already built for them, and the scrappage scheme weighs towards this because your last renault is probably completely fucked at 9.5 years. so if the tax went on the oils, it would boost this guys campaign to get us all driving shitty electric renaults.
Has everyone seen the french electric car scheme on late night tg4, sorta like dublin bikes?