I re-read that part and I think the sentiment was more like "If you are a great computer scientist you have most of the skills you need to be able to use R."

Regardless, even if the recipient has Excel, I think it is poor form to insert an Excel object into your reports and emails. The copy/paste menu allows you to paste charts and graphs as images, and it's a superior option to inserting an actual graph (or table) the majority of the time. Not only does it preserve the formatting, and allow better cross-platform compatibility, but documents with images instead of graphs open faster and are generally smaller.