another reason , if you have a disabled child, it is hard to get them out of the car and you need more room either side
My DD (sn) can walk, but has no road sense at all. Yes, we could probably park further away, but then I would also hit the car next to me whilst struggling to get her out of the car as she can't get out herself
I have 4 year old twins. My SN can just run off and having to walk across a car park can be hard sometimes. I know you could say many 4 year olds would run off. But I can only compare her to her twin sister, who can get out of the car seat herself and walk nicely with me