"idiot pram users clogging up the accessible loos"
Arrrgghhh. Actually I think idiot pram users probably have more sympathy for disabled users than the average person, as they are more aware of the logistics of getting in somewhere.
The issue does not lie with the pram users but designers.
As other people have pointed out, they would not leave their pram unattended for fear of theft which is actually pretty reasonable given the cost of them. They are likely to be uninsured if not locked up (in a similar way to bikes). When was the last time you saw somewhere to lock your pram up near toilets?
A couple of weeks ago, I had the joy of using the Trafford Centre baby change facilities for the first time. Planning was approved in 1996 and it was completed in 1998, so not in the dim distant past before accessibility laws. I was shocked. It had three bays, but there was so little space in there that you could just about fit in two prams, but certainly not three. Which rather defeats the point. There is no where to leave your pram outside. It was mid week during the day, and during that time several people had to go away as there wasn't space in there for them. I dread to think what its like on weekends.
Incidentally I was there last week and went for food with my MIL. I was directed by staff at the restaurant to their disabled toilet which doubled as a baby change. The ladies and gents were upstairs so would have been completely inaccessible and were too small anyway.
So what should I have done in that situation? And what do you do if the baby change facilities are not fit for purpose and there isn't enough of them?
Its not a question of 'idiot pram users' being somehow selfish. Its an issue that shopping centres and supermarkets are being built to produce as much retail space as possible to generate revenue without any thought being given to those who use actually use them. Its more inconvenience rather than a convenience.
Ultimately unless that's legislated for too, then there will always be this problem.