I am appalled by many of the comments on this thread.
Yes, it was a 'tad ableist' - people with disabilities can raise children well without necessarily being able to learn to drive!
People with not enough money to buy driving lessons and then buy and insure a car can also raise children well. And so on through all the other assumptions put forward as definite solutions on the thread (and splitting hairs rather, the woman might go into labour at significantly sooner than full term, so the partner wouldn't have had 9 months to learn, get and pass a test then, would they?)
There will be many mothers in labour who may need, for a wide variety of circumstances, to call an ambulance. And some who probably don't need to but call it anyway and will be triaged appropriately by the call handlers. So I agree, if you are pregnant reading this and feel YOU need to call an ambulance, err on the side of caution, call and then they will decide whether/who to send to you and how quickly. Where I live, we have many paramedics who work singly with a car or motorbike, so you might well get one of those first, depending, and they will assess.
If only this country (I'm in England) had the necessary number of midwives available to attend for home births and in early labour to give assistance and advice, like we used to, then we wouldn't have this problem to the same extent, would we? (Not knocking midwives - there's a chronic shortage which means that the way maternity care has to be delivered to get the best outcomes for the most people is less than ideal.)
I think it's ridiculous and unpleasant to lump labouring mothers - who at the very least have a genuine need for some medical attention in the relatively near future (and especially as first timers, can't always make the "obvious" (not obvious) "correct" judgements about how urgent it is) - in with timewasters of all the other flavours who clog up the system.
I'm in the camp that says it's impossible to say if it's unreasonable unless you are the woman or were otherwise intimately involved in the whole thing and actually understand the circumstances fully, which isn't that likely because you'd have to be a very intimate confidante of the woman concerned to be SURE you have the full picture (mentally, emotionally, physically and practically).