Comment by jchw

> Literally no user cares what language a project is implemented in

I think this is true but also maybe not true at the same time.

For one thing, programming languages definitely come with their own ecosystems and practices that are common.

Sometimes, programming languages can be applied in ways that basically break all of the "norms" and expectations of that programming language. You can absolutely build a bloated and slow C application, for example, so just using C doesn't make something minimal or fast. You can also write extremely reliable C code; sqlite is famously C after all, so it's clearly possible, it just requires a fairly large amount of discipline and technical effort.

Usually though, programs fall in line with the norms. Projects written in C are relatively minimal, have relatively fewer transitive dependencies, and are likely to contain some latent memory bugs. (You can dislike this conclusion, but if it really weren't true, there would've been a lot less avenues for rooting and jailbreaking phones and other devices.)

Humans are clearly really good at stereotyping, and pick up on stereotypes easily without instruction. Rust programs have a certain "feel" to them; this is not delusion IMO, it's likely a result of many things, like the behaviors of clap and anywho/Rust error handling leaking through to the interface. Same with Go. Even with languages that don't have as much of a monoculture, like say Python or C, I think you can still find that there are clusters of stereotypes of sorts that can predict program behavior/error handling/interfaces surprisingly well, that likely line up with specific libraries/frameworks. It's totally possible to, for example, make a web page where there are zero directly visible artifacts of what frameworks or libraries were used to make it. Yet despite that, when people just naturally use those frameworks, there are little "tells" that you can pick up on a lot of the time. You ever get the feeling that you can "tell" some application uses Angular, or React? I know I have, and what stuns me is that I am usually right (not always; stereotypes are still only stereotypes, after all.)

So I think that's one major component of why people care about the programming language that something is implemented in, but there's also a few others:

- Resources required to compile it. Rust is famously very heavy in this regard; compile times are relatively slow. Some of this will be overcome with optimization, but it still stands to reason that the act of compiling Rust code itself is very computationally expensive compared to something as simple as C.

- Operational familiarity. This doesn't come into play too often, but it does come into play. You have to set a certain environment variable to get Rust to output full backtraces, for example. I don't think it is part of Rust itself, but the RUST_LOG environment variable is used by multiple libraries in the ecosystem.

- Ease of patching. Patching software written in Go or Python, I'd argue, is relatively easy. Rust, definitely can be a bit harder. Changes that might be possible to shoehorn in in other languages might be harder to do in Rust without more significant refactoring.

- Size of the resulting programs. Rust and Go both statically link almost all dependencies, and don't offer a stable ABI for dynamic linking, so each individual Rust binary will contain copies of all of their dependencies, even if those dependencies are common across a lot of Rust binaries on your system. Ignoring all else, this alone makes Rust binaries a lot larger than they could be. But outside of that, I think Rust winds up generating a lot of code, too; trying to trim down a Rust wasm binary tells you that the size cost of code that might panic is surprisingly high.

So I think it's not 100% true to say that people don't care about this at all, or that only people who are bored and like to argue on forums ever care. (Although admittedly, I just spent a fairly long time typing this to argue about it on a forum, so maybe it really is true.)