You are absolutely correct that these things typically do not happen with the major car manufacturers, and that Tesla needs to get its act together. But it is worth considering the other car manufacturers have been doing it at scale for a much longer time often with better understood materials and technology.
People often ask "What are the other carmakers going to do to compete?" and this is exactly one of those things that they'll bring to the table.
The opinion and memery about this brand is just unbelievable. Cars are big and complicated devices and selling them is equally complicated, and I'm sure there are people who have bad experience buying them, as is basically inevitable. But the overwhelming majority of owners think it's great.
[1] If you don't count the incessant, obsessive checking to see what the current delivery estimate is, of course.
I don't care at all what the overwhelming majority of owners think. Maybe 95% of customers are happy to have saved a few hours in a dealership, but when the 5% are without a car for six months that's pretty cold comfort.
The problems I am discussing are very serious. It is not enough for them to be uncommon; they must be unheard of.
This is sadly quite common right now. If you own any vehicle with Tesla production levels, it's possible there's a shortage of certain parts for it.