I know i can implement an up-tree or a doubly-linked-list safely just fine. I do not need to have a straightjacket put on me that prevents me from doing that.

If you wish to use it, do. If you want to force your employees to do it, feel free. Telling everyone else how to live their lives and do their jobs is a dick move.

But the point is that there is so much provably safe code that the borrow checker doesn’t understand. Let’s not get confused: Rust borrow checker forces you to write in a very narrow space that it can understand, which is a very small subset of safe programs. Sometimes it’s worth it to be so constrained, others simply don’t.