RMS, among others, objects to the very term because it encompasses so many different things and that leads to ambiguity, preferring instead to refer to rights individually, e.g. trademarks, copyrights, etc.
For those who simply want to protest, though, people have been using terms like 'intellectual monopoly' or 'imaginary property' or the like. But that gets you right back to lumping them all together again.
You are indeed correct, and I usually agree with RMS on this[1]. It's a bit hard to answer posts talking about IP without using the term yourself, though.
Also, while it's clear that there are different motivations behind Copyright, Patents and Trademarks and it's often important to make a clear distinction between them, I object against them due to the same reason (owning abstract concepts is absurd to the point of insanity), so I do tend to lump them together in a context such as this.
For those who simply want to protest, though, people have been using terms like 'intellectual monopoly' or 'imaginary property' or the like. But that gets you right back to lumping them all together again.