There are already tools out there that do the rip-to-unencrypted-ISO job, especially on Linux. Why bring another out, if it isn't going to add anything?
An ISO is far from the most efficient way to store movies, unless "duplicating the disk experience" is high on your priority list. Searching for "linux rip bluray iso" came up with many free options. Switch "bluray" with "dvd" came up with even more.