Yes, they do all go the same way. People in wheelchairs or unable to walk at all are not the only 'worthy' people.
I'm 53 and have Autism, ADHD, Ehlers-Danlos Syndrome and Osteoarthritis. I can walk a short way, but it's crippling. I can suffer a dislocation of my joints at any time, however, and then I'm fucked.
My mother has bowel cancer. She has a colostomy bag. She's not left the house in four years apart from medical appointments. If her bag goes into overdrive whilst at an appointment, then she will literally have shit pouring out of her stoma. She becomes very distressed when this happens and it wouldn't be nice to have her walking across a full car park with that on show. It's made her a shadow of her former sense. I've never applied for a BB for her because I have one myself which I can use for both our benefit. She does have a radar key, and would also be entitled to a BB in her own right.
My 13 year old DD has EDS, Autism, ADHD, Pernicious Anaemia, Hypothyroiditis and severe anxiety. When she has a meltdown (this happens a lot during medical appointments as she's subjected to all sorts of horrible procedures due to multiple other medical conditions) I can't just leave her as she would likely run into the road and be run over. As it happens, again, because I am a BB holder myself, I've never applied for one for her, but, like my Mum, she would be entitled to one herself as she receives the required level of DLA.
I wouldn't wish any of these conditions or ailments on anyone. They are restricting, upsetting, and worse still - as evidenced here - extremely misunderstood. It's totally crap when your life is turned upside down and doubly worse when people judge you and deem you 'unworthy'
Due to the combination of all of the above, we attend our local hospital around two to three times a week. It causes no end of anxious feelings as the car park is busy, and I arrive an hour before appointments just to make sure I can get a BB space as theres often a queue. I've had panic attacks and been in tears on numerous occasions before I got my BB. Ive also sat for hours in the passenger seat prior to having my BB as I used to get regularly blocked in on the drivers side in regular spaces. It's a shit way to live tbh, and nobody I know personally gets it. Almost everyone judges without a clue what my life involves.