The first thing is to realize that understanding about the mind, and understanding about the world, is not common knowledge in this world. And, that there are many wrong views in the world. I think that is more in line with one of the Compassion/Lovingkindness meditations I gave at the beginning of the retreat. That is, understanding that sometimes idealism arises when people are closest in conditioning to us, or when they have good fortune, "They should know better, etc". If in that case, this type of idealism arises, then we can try to reflect on the factors in the society that are very strong and that it conditions them in these unbeneficial ways.
It is common that people are bombarded everywhere, from advertising and TV and teachings that tell them that happiness lies out there somewhere, and that suffering comes from your childhood, and the insufficiencies of your mother, father, etc. So it helps to understand that there are a lot of pressures in society to believe a certain way. Our teachings in school are often directed towards making ourselves functional parts of society, teach us how to make some money to support ourselves. Yet we are not often given much instruction on how to take care of ourselves emotionally. Or to understand and develop Compassion/Lovingkindness, and all the beneficial qualities.
We must keep in mind that Dhamma, especially the Four Noble Truths, is not common knowledge in the world. And it is difficult, sometimes, to remember. Some people do start to understand that Dukkha does exist in the world, but to come to the next point, of understanding where it comes from, takes a bit of mental development or exposure to different ideas, and many people haven't had exposure to these different ideas. Sometimes there are some perceptive people who have realized, "Ah, Dukkha does exist" but they may not know any way out of that. And looking at ourselves, we try to remember how difficult it is to deal with these hindrances in ourselves, so that we develop a certain amount of compassionate understanding of how difficult it is to deal with these hindrances. This is so we can develop more compassionate forgiveness of others, too.
As to, "Disappointment about not being able to help themselves, or even want to help themselves", reflecting on Kamma is very helpful for letting go of disappointment. Everybody is the owner of their own Kamma. Actually one can do a type of Kamma reflection. As we do with Compassion/Lovingkindness, bringing people to mind and thinking about their difficulties, and then actually instead of a Lovingkindness phrase, saying, "They are the owner of their own Kamma." This can help us to develop a more Equanimity.