I don't have a strong stance on the overall issue of whether it made sense for them to port like this, but I feel like this misunderstands the value proposition of Rust. The point of Rust is not and has never been "make literally everything safe", it's "push the unsafe boundary as low as possible and keep as much as possible above it so that you can reduce the surface area for unsafety and more easily find bugs in the unsafe code". For some things, that means you can rely only on unsafe code that's in the standard library implementation, which is awesome. For others, you might need to rely on FFI to interface with external libraries, and that's obviously less ideal but still provides tangible value. In the worst case, you might need to write unsafe Rust code yourself, but you can at least take efforts to minimize the surface area of it by wrapping it in safe abstractions that enforce the invariants you need to uphold safety.

The idea that "anything other then pure safe Rust is useless" is common (even among some Rust proponents, but generally not the most experienced ones), but it's a pretty fundamental misconception of what Rust actually offers. Safety is a spectrum, not a binary, and while the extreme end of "everything is guaranteed to be safe no matter what" is nice when you can get it, Rust is literally designed to solve the problem of giving you the ability to slide along the spectrum to calibrate to the most amount of safety you an achieve rather than being all-or-nothing.

If you still think there's no value in enforcing safety outside of the lowest level stuff like JIT, I'd suggest being more explicit about why you're confident that memory safety bugs wouldn't be a concern outside of those contexts. I've yet to hear an argument for why I shouldn't be concerned about memory unsafety in even relatively mundane code in memory unsafe languages that doesn't basically boil down to "just be really really careful", which I'd argue has been empircally shown to not work even a little bit no matter how skilled the programmers writing the code are.