Look, cars are complicated. Manufacturers write repair manuals and stock parts based on expected failures. Not every conceivable failure is going to be in those manuals. In this case there was a valve that was part of "The Battery Pack" as far as the manual was concerned, but that had a localized failure more that could have been repaired with a targetted replacement of a single part.
And it wasn't in the manual. And yeah, that's sort of an engineering failure. They should have anticipated this low-hanging-fruit kind of repair (just as they do for other very common stuff like brake calipers or shocks or whatnot). And they didn't. Shame on them.
But that's not a systemic failure. They just didn't write it up.
What are you really asking for here? That Tesla empower its local service centers to do their own engineering work on a 400V electrical system and decide for themselves how to disassemble and reassemble the battery pack in a safe way just to save a handful[1] of battery replacements? Does that sound like a good idea? Seems like we'd be right back here with entirely different (and IMHO more justified) anti-Tesla safety flame wars.
[1] So far as anyone can tell, this is in fact the only such valve that has failed on a wild Tesla. It's not like these things are dropping everywhere.
Yes. This is what certifications are for.
> and decide for themselves how to disassemble and reassemble the battery pack in a safe way just to save a handful[1] of battery replacements?
No. See above.
The Tesla fleet is aging every day. This type of repair is going to become much more common and the lack of recourse is going to start to decimate the used car value. If Telsa's long game is to sell trips and not cars it might not be a terrible plan.
No... no, it's not. Manufacturer certifications are designed to provide liability protection for repairs done by people given training on how to make specific repairs to specific systems. What you're asking for here is for someone to independently determine that this valve can be replaced in isolation from the battery it's attached to. That's not the same problem at all, and good luck getting an insurer to cover that kind of nonsense under a "certification" contract.
> This type of repair is going to become much more common and the lack of recourse
Again, that's just simply wrong. Small part repairs are routine and common in the Tesla world just as they are everywhere else. The overwhelming majority of repairs don't involve replacing the battery pack! This controversy was about a very specific small part that happens not to have an individual part number nor disassembly spec.
And maybe it should! But your generalization is just silly. Tesla doesn't treat repairs any differently from any other manufacturer, period. You got sold a line that matched your priors.