Earlier quoted context omitted.
>they continue to work on their own personal homegrown BI-suite in excel. Why aren't you providing your dashboards via Excel, then? What exactly does the fancy BI software do that Excel won't? I have used Qlikview but not Tableau or Informatica, and I'm a bit fuzzy on what people mean when they say "Power BI". Is using Power Query what you would call Power BI? Or does that mean using the data model stuff? Power Query…
PowerBI is kind of a MS Access for BI. It loads data from your warehouse and gives both visual builders and query interfaces to data. IE, it's a specific product name - the data viz tool from MS to accompany their other services.
I've used both DAX and M (Power Query) via recent versions of Excel. Obviously there are plenty of ways to interface with data.
https://en.wikipedia.org/wiki/Power_Pivot says both Power Query and Power Pivot are part of Excel.