Ruto has to balance policy vs. the reality on the ground. I keep listening to Ndii and I think in the long-term, it sounds like his plan will work, but Ndii doesn't have to deal with the political consequences, Ruto does.
Ndii's current answer is pretty much that he warned kenyans for years that Jubilee's mega infrasctructure programs and accumulating debt would come back to bite them, but at the end of the day, governing is not easy.