Is it unreasonable of me to lose all interest in linux development upon seeing a command line exe to add two numbers is 3.1MB, and not just that but have it's being 3.1MB treated casually as just interesting/cute by a linux dev?

It may be worthwhile to point out that the example is built in debug mode, and also Rust is including the whole standard library in the output. Re-configuring some low hanging fruit [1] reduces the binary size on my test machine to 27K. This is still not small, granted.

[1] https://github.com/johnthagen/min-sized-rust