I think it's down purely to preference only. For example, I originally used only vi for a long time, maybe 2-3 years. Then I worked with someone who was a pico/nano freak, loved it for whatever reasons, so I used that whilst I worked with him. Ever since I've leaned both ways (lol).

However it's important that people learn some vim commands because it's really the "native" editor that you may one day be forced to use... If you don't know how, you're up shit creek I guess.