I think one of the reasons why P & C spaces are near to the store is to minimise the distance parents have to hike trollies, babes in arms, pushchiars, etc. It also minimises the distances tots have to walk, which again minimises the potential for that fatal moment of distraction where a little one gets separated, and can run across the traffic lanes.
On a separate note, our local Sainsburys has a cool deterrent for anyone parking in a Disabled bay - the stick a large poster on the driver's window confirming in massive black letters that the driver parked in a Disabled spacec without an appropriate blue badge. The poster is stucj on with seriously sticky glue, getting it off is a nightmare, takes ages, and gives the drive plenty of time to consider their selfish and inappropriate behaviour.
And yes, I hold my hands up and confess that i speak from personlal experience - for which I am duly ashemed and make no escuse - but I have never done it since, it was about fifteen years ago!!