I'd wager that ANY person who actually uses CLI tools to do things does not want, nor need, to write full sentences to do these things. Everyone that uses CLI tools always says they do so because it is the fastest way possible to do X. That point becomes moot once you have to write sentences.
I don't know - I live in the terminal, and I definitively wouldn't use it for regular commands (sed, grep, tar, etc), but if it was smart enough, I could see myself using it for software that I rarely use and which has complicated options.
For example, I'd rather type
please convert movie.avi to h264 at 720p with subtitles from movie.srt
than having to read the man page of avconv each time.
Bonus points if it could print the translated command before running it - it'd double as a learning tool.
