Because the language's resource allocation style is not so much a "cross-cutting concern" as something which is all-pervasive across every single non-trivial program written in that language. For a long time, we had four styles: Static allocation, purely manual management of dynamic resources, garbage collection (usually with manual management of some resources), and "don't worry about it" for truly high-level declarative languages. RAII adds something to this, but C++ didn't give up new and delete (or malloc and free... or anything whatsoever) so it isn't really a wholly new paradigm. Rust, however, adds something that's genuinely new to most programmers, and it requires a re-working of the thought-styles, so it's worth thinking about whether it's worth it.
> it's worth thinking about whether it's worth it.
Totally agree we need to evaluate the trade offs of various paradigms. But, I think the most important aspect to understand is the impact on maintenance as opposed to writing.
I’m not sure what my ratios of time spent on reading vs. writing vs. debugging code are, but I am certain writing is what I do least, which is why I’d like to see more research on total cost of ownership.
