Did you try to Uninstall any Module in drupal before?

With every module, you will find a file "INSTALL" to guide you to the installation process, but you will not find any file called "UNISTALL" !! what if i want to remove a module? just delete the .module file?

What about the shit database tables? Who will remove it?
I hope that i can see a uninstall script with every module to remove and rollback the database changes.