Problem in Rust adoption

There's no supporting details?

"C++ programmers find it difficult." Says who? I doubt someone who slogged through enough pain to learn C++ would be fazed by the weird parts of Rust.

The Rust language is not at all a significant barrier to its adoption. I think that the fact that Mozilla refuses to standardize its development and has a history of political-correctness inclusivity is a bigger barrier to its adoption. Especially given that C++ has been around for so long already, is always (very slowly) improving, and is already standardized. It's not a great language in the sense that it's FUN to program in, but neither is Rust, and even if it was, it's not a good enough reason to throw away c++.