The Rust compiler doesn't produce warnings out of zealotry, but rather as a consequence of pre-1.0 historical decisions. Note that Rust doesn't use any syntax in pattern matching contexts to distinguish between bindings and enum variants. In pre-1.0 versions of Rust, this created footguns where an author might think they were matching on an enum, but the compiler was actually parsing it as a catch-all binding that would cause any following match arms to never be executed. This was exacerbated by the prevailing naming conventions of the time (which you can see in this 2012 blog post: https://pcwalton.github.io/_posts/2012-06-03-maximally-minim... (note the lower-cased enum variants)). So at some point the naming conventions were changed in an attempt to prevent this footgun, and the lint was implemented to nudge people over to the new conventions. However, as time went on the footgun was otherwise fixed by instead causing the compiler to prioritize parsing enum variants rather than bindings, in conjunction with other errors and warnings about non-exhaustive patterns and dead code (which are all desirable in their own right). At this point it's mostly just vestigial, and I highly doubt that anybody really cares about it beyond "our users are accustomed to this warning-by-default, so they might be surprised if we stopped doing this".

Ah, thanks for the info! I do think this default does have some ramifications, especially in that binding casings are typically changed due to it even for "non-native" wrappers which I find materially makes things more difficult.