Just come back from The ASDA
they have an electric gate to leave the self scan and Scan&go sections
It is supposed to be closed and only opens when you approach from the shop side
As usual it was fixed at open
I dunno why - but in spite of the apparently huge rate of shoplifting - the big supermarkets seem to actively disable and ignore possible methods of making it more difficult
this could be
a) it just generates major problems if it indicates a problem as British people are rather bolshy if challenged
b) putting something in people way annoys people and makes them think of going to another supermarket instead next time