For the same reason that we don't use the concept of race between humans, because it's a spectrum with no distinct delimitation point.
You will find people of all shades of colors, all types of hairs, etc. just like you will find autistic people with different sensitivities, different creativity, different interests, different needs, and you can fill the whole spectrum, you won't get a gap between "autistic" and "asperger".
There are quality issues but the success of Tesla was mostly due to the hype created by Elon, now that most of the people that care the most about the environment dislike Elon of course their sales drop