I've seen anything and everything passed around in Excel.

Project timelines, infrastructure descriptions/allocations, working on systems that allow users to deposit parts of their workflows via spreadsheets (financial related), some RFPs come and are returned in Excel form.

I can't speak to any exceptions but I personally use Word and Excel semi-daily.

I also believe there are a variety of people on HN beyond traditional strictly software devs. DevOps, Cloud-related (myself), Product Managers, Project Managers and the like.