Why do people tell suicidal victims that they should think of others?

Life is overwhelming. Thinking of others is a good thread, though. Suicidal people often feel, and behave as if, they're islands when in fact they're part of a social network that they just can't appreciate. Thinking of others first, before the self, gives a reason for one to exist: to bring net benefit to the larger community. If one believes that s/he is alone in the universe (solipsism), then it's much easier to self-terminate.