I recognize the difference between the two -- but those two concepts are not inseparable, the one causes the other. The restrictions that the constitution imposes created a set of legal rights.
A law that says "the government can't legally do [x] to me", by definition, creates a legal right that I have "a right not to have the government do [x] to me". They are semantically different in perspective, but causal in relationship.
Yeah, I completely understand your point of view. I think if the intention of the Bill of Rights was to grant legal rights they would not have used the language they did. All the talk of "infringement" and "enumeration" make it clear they were going out of their way not to grant rights.
If people said "the constitution grants the right for our free speech not to be infringed" I'd probably ignore it. That's not how any discussion goes though.
Here's why I think this matters in this instance. By saying the 4th is "just a legal right," you are saying that the Constitution only grants it to certain people and the government can spy on anyone else. But by saying it's only a limitation, there's no qualifier on whose rights they can infringe.
A law that says "the government can't legally do [x] to me", by definition, creates a legal right that I have "a right not to have the government do [x] to me". They are semantically different in perspective, but causal in relationship.