Maybe because the hailing for yet another "safe" language starts to feel kinda repetitive?

Java, C#, Go, Rust, Python, modern C++ with smartpointer,...

I mean a concepts for handling files in a safe way are an awesome (and really needed) thing, but inventing a whole new programming language around a single task (even if it's just a transpiler to c)?

One of the advantages with wuffs is that it compiles to C and wuffs-the-library is distributed as C code that is easy to integrate with an existing C or C++ project without having to incorporate new toolchains.

> Maybe because the hailing for yet another "safe" language starts to feel kinda repetitive?

Ah yeah, because the endless stream of exploits and “new CVE allows for zero-click RCE, please update ASAP” doesn't feel repetitive?

> I mean a concepts for handling files in a safe way are an awesome (and really needed) thing, but inventing a whole new programming language around a single task (even if it's just a transpiler to c)?

It's a “single task” in the same way “writing compilers” is a single task. And like we're happy that LLVM IR exists, having a language dedicated to writing codecs (of which there are dozens) is a worthwhile goal, especially since they are both security critical and have stringent performance needs for which existing languages (be it managed languages or Rust) aren't good enough.