I think the process by which they discovered their synthesis method qualifies as experimental physics. Keep in mind that it is still hugely infeasible to produce industrial quantities of the stuff.
Also, as the parent says, a review of the literature shows a wealth of interesting physics being done with the material, much of it unencumbered by aspirations of possible engineering applications.
Of course; semantics refers to meaning of words; obviously disagreement between two parties will be about the meaning of words. Probably, you mean "polemics."
Physicists are professional doctors of philosophy; by tradition; they own the right to define any theoretical subject and they defined physics as the fundamental science defining nature; which is not correct. Physics is just one way of looking at nature.
No, I mean this is a confusion about the meaning of a word (namely, "physics") not a dispute about facts (empirical or normative).
By the way, saying an argument boils down to semantics is not vacuous. If I disagree with Bob about whether the moon will be full tonight, we have no disagreement or misunderstanding about the meaning of words.
Also, as the parent says, a review of the literature shows a wealth of interesting physics being done with the material, much of it unencumbered by aspirations of possible engineering applications.