The logic of spin-2 gravitons is that GR predicts gravitational waves, and in QM, all waves are also particles. Gravitational waves are seen as waves of spacetime whereas gravitons are mediated as particles on fixed spacetime. Spin-2 gravitons can reproduce GR using QFT in the weak field approximation. But perhaps nature does not allow the existence of fundamental particles greater than spin 1, and that there are no gravitons associated with gravitational waves b/c the properties of spacetime which makes gravitational waves possible, do not allow the wave-particle duality a corresponding graviton particle. Is it possible then to have GR and GR waves, but no particles, (only example of wave-particle duality not applying) b/c spacetime can carry waves, but is not itself particle, and the quantum spacetime is some sort of fundamental quantum structure. Gravity is not a force mediated by gauge bosons, as EM, QCD, weak, but curvature and geometry.