Not being determined or disturbed by the ignorance in the world doesn't mean that one is ignoring or unaware of all kinds of ignorant affairs in the surrounding environment. It also doesn't mean that one is emotionless, non-sympathetic, or non-empathetic.
It's merely the correct understanding towards the modification of the minds, towards ignorance and the consequences of ignorance, while respecting the nature of selflessness and impermanence in all and everything, and being capable to let go passionate egoism of attachment, identification, desire of craving and aversion, judgment and expectation, that enable the mind to be aware of all kinds of ignorance and suffering deriving from ignorance in the world, while being undetermined and undisturbed by the ignorance and the consequences of ignorance.
For those who have great enthusiasm to help the world to be free from ignorance and the consequences of ignorance, or to have less ignorant affairs and suffering generated out of ignorant thinking, belief, values, practice, actions and reactions, they need to be aware of what is happening around the world, however, it's very important for them to also have certain degrees of non-attachment and non-identification, so that they are not being determined or disturbed so much by all kinds of heartbreaking inhumanity or cruelty that are (unfortunately still) existing in the world of higher education, science and technology, of higher comfort, convenience and enjoyments, but not free from the influence of ignorance and egoism. If so, they can contribute a lot, while looking after themselves, without loosing their own peace and sanity. The world is desperately in need of more such selfless compassionate beings to balance the off-sided equilibrium of the world, where greed and selfishness are getting heavier, unfortunately.
Some people might choose to ignore the ignorance in the world, by closing their eyes and ears, or moving away from social medias and current world/local news, not seeing and not hearing anything in the world and in one's surrounding environment that can be 'disturbing' to the state of their mind, so that they will feel better and happier. That's their freedom, and there's nothing wrong to be looking after the state of one's mind.
In fact, those who can't take in anymore disturbing or frustrating news in the world about all kinds of ignorant worldly affairs deriving from the ignorance of selfish human beings, as they might not know what is non-attachment and non-identification, then by making an initiation and effort to step back from the world, of not seeing and not hearing, or not knowing and not aware of all kinds of ignorant happenings in the world, is the best way to help the world to have more peace by helping oneself, to maintain certain degrees of peace and quietness, to be looking after one's mental health before loosing it. It's not selfish at all, as one isn't generating or contributing any harmful destructive actions and reactions into the world, which is already a great contribution to more peace and harmony.