We've had multiple bills proposed by multiple countries for government mandated backdoors. Multiple articles refer to how these bills would create backdoors, multiple computer security experts say the bills would create backdoors in the software. Under your definition of the word they'd all be using the word incorrectly because logically no bill could create a legal backdoor by definition.
It's seems there's a semantic schism on "the point in software where security is weak enough (either purposefully or unkowingly) for 3rd party access by a 3rd party" and "the point in software where security is purposefully weakened for 3rd party access by the legal requirement of a 3rd party" there's definitely a distinction but I generally conflate the two, perhaps incorrectly, under the word backdoor.
If you've got another more appropos word for this purposeful and legal weakining of security for non primary user/provider access I'd love to know it because sadly I feel I'd use it fairly often in the coming years.
These articles use the word "backdoor" for effect, for example <https://www.schneier.com/blog/archives/2021/08/apple-adds-a-...>. The bills you refer to by multiple countries simply want their own in-house wiretapping apparatus, because they don't want to be dependent on the US. Specifically, I'm thinking of EU's "chat control". Ironically those who oppose it are unwittingly doing the bidding for a more powerful US. The internet is fully wiretapped and there is no end in sight.
No they use the word backdoor because there is no better word for these pathwatys/purposefully created weak spots in access to the software. Seriously please give me one that emphasises the security detriment to the 1st party user and i'll happily use it instead.
I'll also add that ironically those who don't oppose these bills are unwittingly doing the bidding of strategic adversaries as demonstrated quite adequately by the PRC here.
It's seems there's a semantic schism on "the point in software where security is weak enough (either purposefully or unkowingly) for 3rd party access by a 3rd party" and "the point in software where security is purposefully weakened for 3rd party access by the legal requirement of a 3rd party" there's definitely a distinction but I generally conflate the two, perhaps incorrectly, under the word backdoor.
If you've got another more appropos word for this purposeful and legal weakining of security for non primary user/provider access I'd love to know it because sadly I feel I'd use it fairly often in the coming years.