Obviously I having some fun with it. Developer/technician/hacker users a different audience. In my office for instance, people can use 'doz/osx/nix. If you walk around, 95% of every monitor you see has at least one terminal open. These are people doing totally different types of work for all sorts of projects.
By mainstream do you mean the 1% desktop share or in the GNU/Linux world?
Actually it was this PDP-11 mentality one of the reasons I eventually moved back into Windows / Mac OS X worlds.
I had my share of CLI starting with Timex 2068, AmigaDOS, MS-DOS, multiple UNIX flavours in the 80 - 90's, to keep doing it daily in the 21st century.
Xerox PARC REPLs were way more interesting way of interacting with the computer and live in modern IDEs.