Those spaces, which spaces?
The ones near the front of the store might be much more needed for someone who doesn't have a walking aid, but struggles to walk distances.
I have a power chair, the store could be a fucking mile away, I do not care - I need room to get the bugger out without getting the ramps squashed/myself run over, but I do not need to be two inches from the door.
When I had a manual chair, on the whole I still did not need to be that close to the door, not say compared to someone using a walker or crutches (does depend on if the parking site is on a slope though... I really couldn't do up hill, in fact doing uphill is why I knackered my shoulders and now need a power chair).
There are myriad disabilities, some visible, some not, and everyones needs are different.
Acessible parking spaces for blue badge holders meet some very very basic criteria - wider spaces, near to the store entrance/walkaways. That is it.
Many do not even meet those criteria well - my friend has a side ramp and often finds the disabled spaces useless where they have a shared hatched area rather than a hatched area each, which can mean her ramp is blocked when people assume the hatched area is for 'their space' and park in it to allow greater access to one side of their vehicle. And no, people do not read signs on the sides or rear windows that state how much space we need.
I need safe rear access - but most of the spaces are front of store with bollards in the centre, so you can't reverse in and unload onto the pavement. So I have to unload straight into the road-way, as there is no extra space behind the vehicle and my vehicle is quite long anyway.
I also can't typically use road side spaces where you park alongside the pavement, as there either is no space behind to unload or if there is now, there won't be when I return (again, people do not read signs!).
So the spaces we have now do not meet everyones needs. Idiots going around being the bloody blue badge police need to fuck off!
If you think someone shouldn't use a space, either no badge or you truly think they're using someone elses badge - report to the carpark owner or local authority. If you think they are using someone elses badge, take a note of the badge number and report it.
That is all you can do. It is not your job to approach people and query their use of a badge!