It isn't that I don't think it is a great photograph I just see something more that would make it something I would PAY (capitols intended to indicate a tenfold difference in cost) to have on my wall. It isn't the darkness of the lighting it is the flatness that I'm not all that fond of.
I see what you are saying.
Basically composition SPOT on lighting acceptable to more than acceptable but would probably take months to get quite the right lighting. I'm not sure the dawn or dusk thing would work but catching it on the right overcast day when the light was just breaking through somewhere and I could see people discussing the photograph in one of those haughty big name photography schools. That is of course coming from a newbie but one that knows what he likes.
That was definitely the right choice for the day you were shooting on then. A bright blue sky would do nothing for the photograph.