Oh so because one thing is banned everything else has to be banned?
Frankly I don't care as I neither smoke,eat,drink or use a mobile phone when driving but let's not go overboard.If someone can smoke while driving safely fine.If they can't then let them be done for driving dangerously BUT let's not ban smoking whilst driving for everyone.
As long as drivers use what's between their ears then there is no need for a long list of things to ban.