In many ways the borrow checker is a tool for enforcing safe mutation of values. As a side effect it happens to prevent entire classes of memory bugs, but it also prevents many bugs that aren't related to memory safety. Historically that side effect was the motivation for designing and implementing it, but in practice it's useful as a general guide for writing rigorous and correct software. As a result, I don't think the borrow checker as silly in this context as you're suggesting.