Did you really go ahead and conflate $7,000 and and $40,000? $7000 buys me a decent used car. $40,000 buys me a brand new Toyota Prius (MSRP $24,700) with almost enough change left over to buy a brand new Hyundai Elantra (MSRP $15,345).
$7,000 is not a small chunk of change, by any means. It's a lot less, however, than $40,000. Conflating the two does no one any good.
Your reasoning is similar to a company computing the cost of web hosting using only the initial cost of one server, without accounting for the cost of downtime or multiple backup servers. Maximum effort does not imply a process with 99% reliability is 100% reliable, and that the cost of failure can be written off.
This is not making a claim in regards to Tesla or the accuracy of the $40k figure, merely that cost matters.
Telsa should institute a completely unconditional agreement to replace your batteries should they fail for any reason for $7K (or less).
They are the ones that actually are more aware of what can brick one of these things so let them demonstrate the unlikeliness with their pocket book.
And we both agree that $XK leads to no difference in attention from the owners.