I think it's bad without the rest of the supporting toolchain but it's not axiomatically bad. There are languages with structured editors (e.g. https://hazel.org/), people can use different tabstop settings and even just different editor colours and wrapping settings and I think we can agree that doesn't doesn't hurt anything. Enforcing an automatic formatter is more or less identical to this anyway: you can write your code using whatever style you want but what ends up in the repo is equivalent to the compiler but not identical to what you wrote. You can imagine running your own local formatter on the code before you edit it and running the global formatter afterwards and an observer being unable to tell that that's happened.