This would massively complicate kernel path resolution on many systems. Taking Linux as an example, even in the simplest cases, ~user expansion as typically imp

This would massively complicate kernel path resolution on many systems. Taking Linux as an example, even in the simplest cases, ~user expansion as typically implemented — via the getpwnam(3) libc function, which in itself implies a rather unfortunate dependency — requires reading and parsing /etc/passwd, and may also require access to network directory services like LDAP.