Paradoxically, programmer life would be made simpler if there were some more complex borrowing rules, that would allow (for example) partial borrows of objects, or allow aliasing &mut in single-threaded circumstances where it's known to be safe (i.e. when the data is something primitive like an int, where it doesn't actually matter if it's overwritten while referenced).
But I know there's extra language design complexity that this introduces, and extra codegen complexity (Rust makes certain aliasing promises to LLVM that it isn't allowed to break) so it will take time. But, there are proposals in the works.