I have no idea why so many people give this a bad review other than perhaps they don't know how to use it yet. There is a steep learning curve, but the things that you can do with Tableau once you know how to use it are priceless. Spend the time to learn it. Then you'll love it. Is it quirky? Are there some usability issues that can be improved? Definitely. But it can take millions of rows of complex data and get you the information and/or visualizations you need to make sense of all but the hugest datasets.