wow, knew I'd light a tinderbox here (sorry, been away all weekend).
VP, it is not the distance to the store, it is:
i) the width of the places so that you can get kids in and out
ii) the proxmity to an enclosed trolley park so that you can load up 2 non-walkers/escape artists, without having to carry two plus trolley to the paper towels at the entrance (or give them wet bums)
iii) the proximity of a trolley park so that at the end you can park the trolley without leaving the car full of kids for very long
iv) consider safety issues of getting small children or big bumps (or both) around a busy car park
I do agre that I do feel slightly guilty using them, in that I know they are really there because as a young mum I am a fantastic customer. But then again, a trip to Tesco ain't what it used to be, and I'm gla for the spaces.