Within .profile I try to find out, where exactly (in which environment) “I” am operating. Once I know this, I can set up PATH depending on the environment. Of course on a Synology NAS based on a BusyBox with IPKG (GNU) extensions things look different to my Mac or to my OpenSUSE installations, but still: having .profile / .bash_profile and .bashrc in common is rather intriguing.