Why do people park in cramped places at the supermarket when a few yards away there is space for a bus?

I was at Morrison's car park and munching on a sandwich I bought and while I was sat in my car I observed how people would park up and forward and reverse themselves in to cramped tight parkins nearest to the store and even struggle to get out of their doors having to slide themselves out through a small door gap when only just 20 yards further away from the store there are a whole strip of spacious available parking bays that would make parking so simple.