Kate asks Mikhail why the Others stay on the island if they have a way off it. Mikhail says that Kate, Locke and Sayid would not understand because they are flawed. They are not on the "list" because they are angry (looking at Locke), and weak and frightened (looking at Sayid).
Kate queries Mikhail about why the Others stay on the island despite having a means of departure. Mikhail clarifies that Kate, Locke, and Sayid wouldn't grasp because they are imperfections. They're excluded from the "list" due to their intense emotions (noting Locke's fiery personality) and vulnerabilities (acknowledging Sayid's fear).