Threads such as this one are quite depressing, since they posit a situation that is obviously not in evidence.
Were Tesla to be really bad it would be impossible to have such high owner satisfaction.
That said, there is equally obviously room for substantial improvement. In my ~50 new car purchases I have had good, bad and ugly. My single worst experience was with a BMW dealer and BMW direct also. I also have had outstanding service from another BMW dealer. I cannot list all of them but I will say that Tesla has been, on balance, the best of the lot because there was no dealer in the middle.
In a Tesla accident repair I had lousy results with parts availability, but that was an early P3D. Still I was unhappy. In other situations I have waited months for a transmission replacement when the one in my new BMW failed a month after delivery. The list of warranty repair problems with Porsche and Mercedes is pretty long. However, every one of those involved new models with new technology. Frankly, cars, boats and airplanes have had similar issues.
So, what is different about Tesla? Continuous improvement, OTA updates for almost everything and hardware upgrades too. A Tesla is a complex beast and many people are ill-equipped to cope with a supercomputer on wheels. Fewer are comforted by communication via electronic communication while finding a human being with whom to talk is rather difficult.
It seems to me that most of the 'Tesla has the worst service' rhetoric stems from culture shock. Many people still think about driving to a dealer, talking with a service writer then waiting. It's not easy coping with a mobile service vehicle, a problem resolved via an OTA diagnosis and repair,etc.
As for me I accept the odd quirk because the total experience is magnificent.
