No, Nordhaus was never the problem and policymakers have not been anywhere near as aggressive about climate change as he thought they should be. If everyone had listened to him, we'd be in much better shape. The climate movement's antipathy towards him is a narcissism-of-small-differences thing. The actual problem is that voters only want to address climate change if it can be done without inconveniencing them in any way, which it can't.
For further argument, see: https://www.slowboring.com/p/economists-arent-the-problem-on...