Instead of driving to a starbucks, they- make coffee at home/work?
Is the taste of starbucks that much better that we need to drive to it, use all these extra materials, in the name of our morning drug Caffeine?
I am especially poorly-positioned to answer these questions since I am not a coffee drinker, but it would probably be a good idea for policymakers to figure out how people will react to a policy like this. Otherwise we might end up with a poorly-target policy that either doesn't make things better (on net) or actually makes things worse.