Don't get me wrong, I'm all for shoppers using an evironmentally-friendly transport.
What I object to is the anti-social manners that seem to accompany it.
Look at the picture. This is my local supermarket in a backward part of rural Flanders.
See the bike on the left? It totally blocks the entrance! And no owner about.
I stood and watched for a bit. It was comedy capers. Loads of shoppers with carts full careening all over the place, in an effort to avoid the bike.