The concept of "passive income" is almost a scissor concept. Or maybe only if you couple it with the categorical imperitive. On the one hand, it's so obviously true that it would be great to have passive income. Draw the salary you're drawing now, with some growth, and not have to work. On the other hand, if everyone had access to this capability then society and civilization would grind to a halt. People make things…
The theory of Georgism [1] suggests a way that we could eliminate rent seeking: by taxing ownership of all common resources at the value of the rent they would demand. That way, property owners, telephone operators, etc. would be rewarded for their labor in development and upkeep of the property, but would not be rewarded for ownership of the property itself.