I think, and many do, that the reverse is true.
His economy is not failing because he is not incompetent.
It's going through hard times as is most of the world.
Well, in fairness to you, there are some other failures. Venezuela is also failing for the same reason - a total dependence on the price of oil and a failure to permit the growth of a vibrant private sector.
See the graph in post 29. If you think that Putin is some kind of genius, you can explain why the Russian economy is tanking.