Yeah that “law” makes absolutely zero sense to me. It’s like “be nice” but in a self-sacrificial way which then indirectly sacrifices other people in the long run.
Take browsers, for example. A lot of people complain that browsers try to work around broken certificate setups on servers, but if they didn’t, users would just switch to browsers that did.
Practical? So the adage is just “be liberal because you have to out of practical necessity”? Are you sure that’s the history behind it?