I never understood the shield design. I wasn't involved when the vote happened, but I would have voted for the circle. If you check the
official explanation they say that the shield "design features the historic shield of the official Seal of New York City..."
Which is nice I guess but I do't think anybody knows or cares what the official seal of NYC looks like. Even a google image search for "official seal of nyc" or "official seal of new york city" doesn't turn it up, at least not anywhere near the top of the results, which are filled with NY state seals of seals of other cities in NY like rochester and buffalo.
And when has anyone ever said , written, or thought "You what's cool and really represents NYC? The official seal. Damn skippy." Never. SO I can't imagine the shield ever had much of a chance, except for folks who were very attuned to the whole old MCFC seal similarity, or people who just really like shields.