Vi is a text editor for serious text editing, it takes some getting used to but is chock full of powerful features. Pico is designed for people who occasionally log into a UNIX machine to check mail or something (its origins are in Pine, which is an email client for UNIX newbies). As a programmer you spend all day editing text, so it's definitely worth putting in the effort to learn how to use a good text editor.
After a decade of regular use I'm only an intermediate vim user, but what I know so far really helps with my productivity.
I would say the same thing, except swap vi and pico in your comment :)
I think it's all a matter of what you got used to first. I started out by using vi on some HPUX machines around 13 or 14 years ago. I've just kinda stuck with it ever since because it's on almost every machine I come across, and I can function in vi fairly well.