I'd like this issue clarified I understand that a full nonpertubative quantization of a yang mills gauge theory in 4D is unavailable. is Dirac quantization of classical theory of gravity e.g GR rewritten Ashtekar Variables Variables or some variation of the idea, a viable approach to a theory of quantum gravity, one that can be used to make useful physical predictions and as a tool to understanding quantum gravity. it may not be the final theory of QG but it can still be a useful effective theory, one that approximates full nonpertubative quantization when that becomes available. GR isn't the only possible classical theory of gravity. Dirac quantization of classical theory of any theory of gravity so long as it reproduces GR, i.e Nordstrom to SUGRA perhaps what is needed is a classical theory of gravity that reproduces GR, but is written and formulated in a way that lends itself to be easily quantized via Dirac quantization is a Dirac quantization of a classical theory of gravity, GR, GR rewritten in Ashtekar Variables or some classical theory of gravity that reprodouces GR a viable approach to a useful theory of quantum gravity theory of classical gravity that reproduces GR, but lends itself well to a successful Dirac quantization as an approach to nonpertubative quantum gravity.