Power BI is a great tool for those that need to analyze data, but not all users are equal in their knowledge of PowerPivot, Excel or the underlying data sources. Some users just want to see and act on data. In the current model, users have to have a PowerBI license to even see a report. So, instead of building or buying a separate visualization layer to go over SSAS or SSRS, why not make PowerView extensible? Give me a very economical or even free limited user tier that can only consume web reports, but no Excel access. You can even assume these users are E2/E3 subscribers.