That is a great initiative! For those "shooting in the dark" just because the tax on alcohol is doubled:
1) Fuel tax will definitely rise as soon as the public transport (Rail) is ready to operate. So for now, reducing fuel price by 25% is more than fair (in my opinion).
2) Alcohol is not banned in Qatar, yet, the country still holds the freedom to impose 200% tax on any poisonous or unhealthy stuff. As far as I am aware, the majority of alcohol consumers come from countries with high Income tax, yet, there's no income tax or vat in Qatar yet.