I have noticed this too, been in shops at all hours and parked in the middle of huge empty spaces, when I come out there are cars all around so tight you can hardly open the door.
I Don't think I would chastise anyone for it though lol.
This does my nut in, I'm one of those who will park as far away from the entrance as possible even if the car park is empty, and quite often come back to cars all around when there is still acres of free space - don't mind so much when it's another decent looked after car when it's another careful person with the same mindset, but when it's an old bashed up banger with a barrage of car seats in it gets a tad annoying (I'm sure some people do it vindictively for a laugh).