It you are right - that Telsa buyers buy their near 100k cars without knowing about OR looking at the competition - then you might as well be long on them since their sales & marketing is way more efficient. Your dig is actually a win for Tesla and a bad sign for the ones you mentioned.
I'm not challenging that, in general, Tesla attracts "non-car people" but the suggestion that people that buy AMGs, RSs and 911s are "car people" is nonsense. I'll give you M though.
Regardless of who buys what, because who cares.. let's compare the acceleration performance of a few (0-60 and 1/4 mi):
Tesla Model S P90D - 2.8s / 10.9s
Audi RS - 3.3s / 11.5s
2016 Mercedes AMG GT S - 3.1 / 11.2
2017 Porsche 911 Turbo S - 2.8 / 11.1
These cars aren't even in the same retail category and Tesla is outperforming those that cost a lot more.
Very few 4-door cars offer what the Tesla Model S offers. It's a new brand and seen as anti-establishment, there's not many of them yet, they sell direct and they seem to communicate very well with their customers. Their software and in-car technology is great. People are reacting to many things that Tesla is doing right.
It will be interesting to see how they do as they move downward. It hasn't seemed to hurt Mercedes.