People who are serious about ideas have to deal with the central tenets of the philosophy, not out of context statements. Otherwise, they aren't going to convince anyone of anything.

As to Ayn Rand's statements here, I'm sure it stems from her disgust over altruism and to the evils to which it leads. Altruists are hell bent on bringing everyone down to the same level and they love to inculcate guilt over issues like these. If you want to see direct evidence of what altruism does to people, the results are writ large in history. The Soviet Union, Nazi Germany and other collectivist totalitarian states show clearly how much life is valued by altruists.

The end result of such a moral code is the exact opposite of caring for people, because at core it's saying "You are nothing", “Du bist nicht". Altruism is death worship. Anyone who acts on altruistic premises, whether they know it or not, are acting on ideas that do not value individuals, and we’re all individuals, including those who are handicapped. I don't have that particular lecture, so I can't comment any more than that.