Part III (Fundamental Rights) + Part IV (Directive Principles of State Policy) together reflect the ideals and objectives of the Constitution, forming its moral and philosophical foundation — often referred to as the conscience of the Constitution (as noted by Granville Austin and in judicial pronouncements).
While Part IV principles are indeed moral precepts that guide the state’s policies, Article 37 explicitly states that DPSPs are not enforceable by any court.
👉 Article 37 text:
"The provisions contained in this Part shall not be enforceable by any court, but the principles therein laid down are nevertheless fundamental in the governance of the country and it shall be the duty of the State to apply these principles in making laws."
So, the reason is incorrect because it wrongly claims that Part IV can be enforced by Article 37.