I just don't see how mandating a pattern makes much sense or solves any problem. A counter-clockwise pattern around Roosevelt Island puts you even closer to the buildings...that's sure to inspire public confidence in any "new rules".
I do think that the unfamiliarity of Class B (particularly NYC's) and the intimidation factor of dealing with ATC in Class B plays a big role here. If they had requested Class B/higher altitude, they would be clear of all obstacles - buildings, bridges, majority of other GA traffic, etc. I guess it's just reality that some people are intimidated by ATC and the R/T in a busy airspace like NYC. Because of this, they don't ask for Class B entry and prefer to avoid it altogether - I've always erred on the side of calling up ATC and getting service whenever I'm near busy airspace. It's ok to avoid controlled airspace when you're in less congested areas.
Maybe the FAA should recommend additional R/T training for the PPL - I think it's just 5-10 hours now and mostly at Class D airports. I'm still just PPL (non-instrument) but learned my flying out of RDU Class C and then NYC Class B - I think the experience was invaluable in learning to keep up with the pace of ATC in busy areas like this. I live on the on NJ side of the Hudson and constantly see fixed wing flying very low amongst all the helicopter traffic - I just always shake my head and wonder why people want to hassle with the numerous helicopters. There isn't a lot of sightseeing difference between 800' and 1500' (my opinion).
In every flight, you are required to be familiar with the airspace through which you are about to fly. I don't know why they would have thought a u-turn in a relatively unfamiliar aircraft at 100+ knots at 500-700' AGL in a narrow corridor of unfamiliar airspace was a good idea.
People make mistakes - I just hope that others learn from it and learn to prepare, think ahead, and ask for help if you have any doubt whatsoever.
If you plan to fly near Manhattan, please, call LGA on 126.05 and request 1500'.