I'm actually quite torn on this issue.  I think culturally in Hawaii for a variety of reasons things like plastic bags, plastic containers, rubber bands etc were historically viewed as valuable commodities to collect and reuse.  So from the stand point of the trendy "reduce, reuse, recycle" slogan, local people have reused plastic bags and things other people might consider trash for a variety personal uses.  
So because plastic bags already have value to them for local people. then add the recycle component.  Imagine if all plastic bags costed the consumer a penny (that went to fund recycling) but then you could take the bags to a recycling center and turn them in for money (3 for a penny) just like cans and bottles.  You would have homeless people and other people who use recycling as a means of supplementing income trying to pick up as many plastic bags as possible and cleaning things up.  Perhaps a cultural solution with incentivization would make more sense than a government ban.