NYC has a law requiring cyclists to stay in the bike lane if one is present. Only more civilized cities (like Boston ;) allow bikes to take the full lane. Although traffic moves so slowly there's rarely a point unless the bike lane is blocked.
You're missing the point, which is that bike lanes are frequently in door zones whereas main travel lanes are not (because they are much wider and have more buffer zone).
https://www.youtube.com/watch?v=bzE-IMaegzQ