Well, yes, it's handy to have a Watson, but truth be told, Watson was more than simply a gut to ask Holmes how he figured everything out.  He was reliable aide to Holmes who supplied muscle (and an armed ally) more than once. the movie version played by Nigel Bruce, while always fun to watch, became more and more useless as the series went on. He was a far cry from Doyle's Watson.

I think Robin was intended to be for the reasons usually cited: to humanize Batman and to provide a way in for young readers. No, I tend to think based on my own experience, that I didn't need Robin as my way into Batman comics, but others' mileage ay have varied in the Golden Age. Adopting Robin changed Batman (and Bruce, too) into a much more rounded character who became more than a Terminator robot. 

Suddenly there was risk involved in Batman was doing. What began as a vendetta evolves into a crusade, and a quest for vengeance becomes a pursuit of justice. Though the notion that Batman loved Robin like a son and more was not played up much, when it was, the reader appreciated that beneath the beloved tropes of the Batman mythos, there were two realistic characters at its heart.

Your point about "Robin Dies at Dawn" is well taken, chad, and it made me realize that the story that precedes it it, "The Secret of the Ant-Man," is more than just a nice gimmick. If you'll recall, it features Robin filling in for Batman, who has been gone for a while "on a secret mission." Robin is left to solve a mystery, break up a crime ring and uncover the eponymous secret on his own, and does s splendid job. In that story we see just how well Batman has trained and taught Robin i  relationship that encompasses not just being a father and son, but also master and pupil, comrades in arms and orphans in the storm. 

In the key scene of "Robin Dies at Dawn," we see not just the love and courage of Robin, but Batman's guilt at leaving Robin alone in Gotham City in the previous story and the depth of his love for Robin while also giving us a glimpse of the hero the young Robin already has become.. Granted, this is all in a Jack Schiff-edited Silver Age package, but every once in a while, the gold glimmers amid the dross, and I think this is one of those moments.

It was a wonderful story for young readers, but it also warms the heart of at least one old bastard.