Adherence to halachah is a fundamental of traditional Judaism. And yet, there is the risk that in our dogged devotion to the legal specifics, we will lose sight of some larger ethical values.
This, says Nachmanides, is the reason for the law of doing “that which is right and good”. It is impossible for the Torah to address every single scenario that may occur in life. There will be situations which the Shulchan Aruch will not have commented on.
As such, a person could delude themselves into thinking that because something is not illegal, then it is automatically acceptable. It is this attitude which the Torah comes to challenge. We are expected to think carefully about all of our actions and intuit whether they are both right and good in addition to being legal.
It may be perfectly legal, for example, to make a minyan (prayer quorum) on an airplane, but if it disrupts the work of the staff, and prevents people from reaching the latrines, it could hardly be classified as right or good.