"free to" - of course! Everybody is free to do mostly anything. TFA is making the point that, if your goal is to make software that is broadly useful (and mayb

"free to" - of course! Everybody is free to do mostly anything. TFA is making the point that, if your goal is to make software that is broadly useful (and maybe that's not your goal), then you should try to make the most common use-cases easy and intuitive, even if that means compromising on complex ones or edge-cases.