Earlier quoted context omitted.
If you've ever run tableau server, you know why.
I would very much like to know what particular issues you are having as well? I work at Tableau and I would like to make sure that issues people are seeing are on our radar, if they aren't already.
Also, lack of Sharepoint integration / ability to handle federated login services with OData connectors.
Minor issues though, I'm a huge Tableau fan.