There are several php and jquery files that aren't used in the core and system module, why they aren't removed?

For those users who have a limited server space, means a lot.

e.g: system/js/tabs.jquery.tools.min.js -> integrated in jquery.js, root/user.php, register.php, lostpass.php, pmsgs.php, viewpmsg.php, readpmsg.php, pmlite.php, etc.

These php are integrated into pm and profile modules.