The world, if you were wondering, will look dimly upon second-hand interpretations of a dead, legally irrelevant philosopher if you're caught in the courtroom violating someone else's intellectual property.

If you want to fight intellectual property you first have to acknowledge that, yes, it is a real thing. Our legal system has made it so. Just like physical property is a thing, corporate free speech is a thing, equal protection of the law is a thing, &c.

(why do I feel I just unleashed an unholy flame war from hell with that last analogy?)

However, if many people say "invisible cherry" when they are talking about a door or opening, or means of accessing something, then it would be reasonable to say both that "invisible cherries exist", and to say "the phrase 'invisible cherry' is meaningful."

Also, while there is no set of all sets, I would argue that (again, for some definition of meaningful), the phrase "the universal set(the set of all sets)" is both meaningful and useful.

Also, if you wanted to avoid a flame war with that last bit, it may have been useful to instead claim that "magic" is meaningless due to being inherently self contradictory (by definition). I would disagree with that claim, but I think it would make a similar argument without being as likely to cause a flame war (though I doubt it would happen in either case)

However, I acknowledge that you did not say magic, and I am not attempting to use a straw man as if you had.

Now you say, "Intellectual property is still a meaningless phrase, because flamebait about God and courtroom farts." To me, it just looks like you're saying intellectual property is meaningless because it's an intangible concept you happen to dislike. This is good to impress people on the Internet, but not a good way to analyze or change the system we live in.