I assume that you are talking about an excerpt from Plunkitt's book that is similar to the one presented in the historymatters link below. If so, you are quite right -- Plunkitt is saying that there is no need to reform the political system so as to get rid of political machines such as Tammany Hall.
In this excerpt, Plunkitt makes a distinction between "dishonest" graft (which he says is bad) and "honest graft" which is good. He says that he and the rest of Tammany Hall only indulge in "honest graft." He says that dishonest graft is doing things like extorting money from people or stealing money from the public treasury. By contrast, what he does is, essentially, insider trading. He says he simply uses his knowledge of what the city is going to do (build a bridge, etc) to make himself rich.
So you are not missing anything. Plunkitt really does not think that reform is necessary.