[JoshTriplett]

> Platform support being the big one.

And between rustc_codegen_gcc, projects like https://github.com/FractalFir/crustc, the ongoing addition of backends to LLVM and Rust, and the eventual removal of obsolete targets as hardware goes away, that's less and less of a problem.

[steveklabnik]

I certainly don't think it'll be a barrier forever, for sure.