I can't tell whether you think you are (A) describing the actual meaning of "non-revenue sport" or whether you are (B) merely tilting at a windmill and prescribing your preferred logic for our language.
If (A), then I think you are looking at things rather simplistically. You overlook several points, including:
(1) Revenue to whom? Revenue is less about whatever money that end customers give up than it is about money that an entity gets in. Even within one business, there can be multiple entities within the business such that each entity has its own revenue. The word revenue in "revenue sport" may refer to revenue that the University entity gets from the Team entity, and the word needs not refer to revenue that the Team entity gets from paying customers.
(2) Secondary meaning. Just because you arguably know the meaning of a word in isolation in general does not mean you know the meaning of a specific term in a specific context that includes the word. The word vacuum literally means total absence of, e.g., air. And yet a vacuum cleaner has many particles of air within it. There is no vacuum anywhere!
(3) Usage beats logic. People use "non-revenue sport" in a certain way. You're not going to change the prevailing definition using logic or etymology. For example, if Penn State beats Rutgers and you say "fantastic!", no one will be confused and ask you why you think Penn State's beating Rutgers is so unexpected that it should happen only in a fantasy. Fantastic now can mean good; you can't change that.