As for dialectical - I haven't heard it anywhere, so I wouldn't even call it that. =)

However, as for "uneducated" - I think it only sounds that way because it's unfamiliar. If you think of "I" as merely a pronoun, and consider that pronouns should be able to substitute for the noun they stand for, it seems to work.

And as for not-very-useful - I can think of at least one case. The legalese of "I, Ryan, hereby declare that..." could be refactored to merely: "Ryan hereby declare that...".