This is silly. Rust could not achieve its performance and safety goals without macros and generics. Generics may have been optional for Go (I don't agree, but let's go with it), but there is no way to achieve zero-cost memory safety without generics (while supporting first-class references and dynamic allocation).

Rust generics are deliberately less expressive than C++ templates, in that they're strongly typed. That's why we get so many complaints from C++ and D developers that you can't do certain things. But Rust sticks with its strongly-typed generics, because Rust has always tried hard to strike a balance between code expressivity and maintainability.

This is a terrible example if you want to prove that point, anyway. This 6502 assembler is obviously a total abuse of the system, and nobody will deploy it to production. It's a neat hack, and that's all. Nobody would use an obfuscated quine written in Go to argue that Go is unreadable. This is exactly analogous.

Finally, Diesel is just an ORM. It uses exactly enough features to be an ORM; the only "problem" with it is that it's an ORM.