While email has evolved from plain text to mostly HTML (apart from mailing lists), code still ist text only. Vim is a perfectly valid text editor and productivity in software engineering is not defined by how much your IDE can do.
> While email has evolved from plain text to mostly HTML
You must have a very different set of correspondents than I do. About the only non-bulk, non-plain text mail I get is when the office manager sticks a cute .gif in an announcement.