This language is awesome, but I'm quite conservative when it comes to syntax. I don't like how Rust is trying to move away from C when considering syntax. I tend to prefer languages that can adopt the "C flavor". Python, in my view, does this very well: its syntax is simple, because it borrows a lot from C in its "flavor".
Rust is not doing that, and that's a hurdle.
In my view, the "C flavor" is very important because it's a standard of how people are able to read code. This has nothing to do with the C programming language, I'm just saying that simplicity is what made C popular and easy to use. I can understand that Rust brings very nice innovations, but in my view it should have done so while keeping the "C flavor" as most as it could have.
I admit it's a conservative view, but I tend to believe that a language can be more easily adopted if at its most basic level, it's simple to read for beginners. Rust is not great: I'm not talking about its learning curve, I'm just talking about the "flavor". A language is a tool of expression and communication, features matter less than readability.