From the outside looking in most of the push back against rust seems to be of the "I am too old, never make mistakes, and don't want to learn a new thing late in my career" variety.
I have rarely seen an argument that pushes back against Rust with actual alternative solutions to the problems the rust proponents are trying to solve. It is mostly a bunch of old people letting the perfect be the enemy of the good.
I think you got your last sentence backwards. Because reading it literally, you mean what we have now is perfect. If that's the case, switching to Rust is a waste of time.
No, it makes sense to me. Perfect is not what we have now (as evident to everybody outside of the "skill issue" denialists) but how C/C++ or a new language could get up to par with Rust with some enhancement, and without the latter's idiosyncrasies.