Government over reach into retailers shopping bag use.

Many who oppose retailer provided shopping bags have no clue as to the
origin or actual rate of break down and environmental impact.

Originally canvas bags were used much like the new generation desired
by the Green crowd.  They were discontinued because they would become
dirty and unsanitary or disease ridden just as they will today.  By 1870 paper
came along and provide a clean safe way to transport.  Misguided
environmentalist have discouraged paper bag use.  The true green
product!  Tree are renewable, often 3 replants to 1 cut, old paper
recycled, bags thrown away turn to dirt in short order.  Anti Bagger
CURMUDGEONS don't want to hear about paper because it does not fit
their agenda.  On to plastic, the common belief is its will take a
million years to decompose in landfill, nonsense.  Experts say 10 to
100 years.  I have dug up plastic bags after 2 and there was little
left.  It does decompose into smaller and smaller pieces but so what. 
It harms nothing.  In the Ocean that maybe a different story but why
are we dumping there when there is absolutely NO shortage of space on
land.  Which is contrary to the hysteria started by J.Winston Porter, assistant
administrator at the EPA that authored the first 1981 report claiming
that landfill space was quickly diminishing.  Who by the way later back
tracked when confronted.
As for retailers- it is first a courtesy to the customer to provide a means of carrying products, good customer relations.  2nd it is good for the retailer because the
consumer will not stop buying because they fear running out of means to
carry the goods.  There will be more bags if they want more products.  A
limitation removed.