I see people coming to Rust from all angles. It’s a nice sweet spot. I came to it from Haskell and on my team of three the other two devs came to Rust from C++. I can opine the motivation looks something like this:

* From Haskell - looking for a strong type system (with sum types, typeclasses) but is “widely accepted”. No GC.

* From C++ - looking for low-level capabilities (pointers, references) with improved safety. Improved manual memory management.

* From Python/JS - looking for performance with a familiar feeling ecosystem and a welcoming community

I think the Python and JS folks will have the hardest go of it, but they also have the most to gain.

I went Python → Rust. Rust is high-level enough for me to remain competitively productive with Python, and the type-system just helps so much. I can't tell you how nice it has been to not have to see "Object of type NoneType has no attribute 'foo'" anymore. Also,

  def foo(obj):
    # ...

And me wondering "what is 'obj'?" and then pulling that root … and pulling … and pulling …. Also "data", another just fabulous name for a variable, really narrows the possibilities. Even once you know the "type" of the variable, oftentimes I'd find that the type definition would subtle shift and morph in different parts of the program: they'd all want a Duck, but have varying opinions on what a Duck actually is. You cannot commit such BS with an actual type-checker.

There is more up-front work with the compiler, but it pays off: the code that passes the compiler is of much better quality.

Also, Option<T> is very nice to have when you need an actual Option<T> (i.e., generically), which Python lacks. (No, `None` is not it: You run into problems when T == Option<U>, and you have None and Some(None) — Python's cannot differentiate between the two.) Also sum types in general.

Python and Javascript programmers so massively outnumber all other programmers that they are the majority of people converting to any language.