We could say we don't know. We could admit we don't know why the writer(s) of Mark's gospel wrote it the way they did. And we don't. We are left to imagine.
As The Rev. Nontombi Naomi Tutu writes, "Whenever I read the Gospel lessons in which the disciples figure, I am so grateful. I am grateful because I feel assured that if Jesus chose this group to be his closest companions, there is nothing but hope for the rest of us."
As The Rev. Tutu sees it, "Whenever they are given the chance to prove that they are worthy companions for the one who comes to offer salvation, they always choose the wrong path, the wrong question, the wrong answer. We cannot help but wonder how it is that they spend so much time in close proximity to Jesus and yet seem to insist on refusing to 'get it.'"
The Rev. Tutu concludes, "Over and over, (the disciples) misunderstand Jesus' teachings, seeing and hearing only what they choose. Their ignorance and misunderstanding of who Jesus is and the work he has come into the world to accomplish are what give me hope for us and our world."
The Rev. Tutu's full reflections on Mark 10:35-45 can be found in Connections: A Lectionary Commentary, Year B, Volume 3, p. 404-406. The Rev. Nontombi Naomi Tutu is an Episcopal priest, and a liberatory scholar, theologian, and speaker.