The owner of a rare car will be aware of the difficulty of sourcing spare parts for the car and how very few mechanics will be familiar with working on the car, or in some cases may never have seen one in the metal. If a person wants a car where parts are available everywhere and every mechanic knows it like the back of their hand then they should pick something common like a Vauxhall Astra.
The reason why so few retailers sell parts for rare cars and so few mechanics are familiar with them is simply a case of economics. It’s not economically viable to do so. Focus on providing for more common cars and leave the rare cars to a small handful of specialists. In extreme cases the specialists rarely make a profit and providing parts and servicing is a labour of love more than anything else.
Could the same be said for children with ASD at schools? It’s such a rare condition that providing training in social skills and life skills is economically unviable compared with providing support for children who have difficulty with reading, spelling, or mathematics which are many times more common conditions? A primary school of 400 children may only have 3 or 4 children with ASD at any one time but somewhere between 50 and 100 children have difficulties with reading, spelling, or mathematics at any one time.