SO, the Hudson area is not as heavily regulated as it should be following standard procedure. There is however some sort of regulation to it and it is, I assume, monitored. Everything else would just be plain suicide. One can safely assume that the FAA came up with that perticular piece of regulation after putting some thought into it. Pretty much the same approach they are taking with drones.
I am not a software engineer, therefor I am not commenting on software posts. Honest questions are always fine and welcome, but argueing against the FAA without any deeper knowledge of how air travel works is getting us nowhere.
FInally, the plane that landed on the Hudson had an issue with birds, didn't it? Only that you cannto do anything against birds, dornes are a different thing.
So far the comments from very knowledgeable people seem to say well a plane could fly in there in some exceptional circumstances and then could happen to encounter a drone that is operating in visual range under 400 feet and something could possibly happen. This is also considering that the sky is filled with birds many larger than drones.