no, nobody should, it's silly. especially in the moden age of IDEs that can show you immediately what the type (static and/or dynamic, if your language is that way inclined) of any given variable is at any moment!
i remember having arguments about this in my first job. i thought, and still think, the whole idea was pointless; but my boss swore by it, and i very quickly learned that prevailing culture trumps good taste any day... unless it's your project, in which case you get to set the rules yourself