Spotfire and Tableau are wholly different products, and the choice of one over the other will depend on need. Tableau does allow users to create attractive visuals, but to a large extent it ends there. Tableau is largely a stand-alone environment offering relatively poor integration with the broader business process, data and analytics environment. Spotfire on the other hand will simply go as deep as the user wants to go, providing full integration with business processes, and specifically the emerging Internet of Things.
There is much more to business analytics than visual analysis. Read this competitive analysis by Butler Analytics to learn more.