I’m not sure I agree 100% with this statement, although I do see its point. ESRI has been hugely influential in defining what GIS is, and how it operates. However, I’d hate to see folks like Roger Tomlinson and his work on the CGIS forgotten or ignored. I’m sure there are many others who deserve similar respect.
OK so I was being a little dramatic, but my point was that ESRI is more influential in GIS than Microsoft is in general.