He remarks (in a dismissive manner) that the general Objectivist environment has always been plagued with moral problems, and therefore a Neo-Objectivist ethics is needed to inspire rational, moral and life-serving behavior.
Here’s an excerpt from his lecture (Power of Self Esteem, Episode I):
I prefer to call myself a Neo-Objectivist, “because having had considerable experience with one way of trying to produce moral behavior and seeing the disastrous consequences to which it led I really was forced to deal with the question—either my concepts of desirable behavior were in error or my concepts of how to produce desirable behavior were in error. As it turned out I decided that in some respect both were in error, but while my concepts of what was moral behavior was sometimes mistaken, a great deal of the time in my judgement it was quite valid. But the greater error by far lay was in my notion of how to encourage the development of moral behavior or rational behavior or life-serving behavior.”The Vision of Ayn Rand, “Benefits and Hazards of The Philosophy of Ayn Rand," Nathaniel Branden offers a detailed presentation of why his differences with Objectivism’s morality leads him to refer to himself as a “Neo-Objectivist."