The man, though blind, sees Jesus better than James and John - and the other ten disciples who are indignant (Mark 10:41). We do not deserve the things for which we pray; all we can beg is that the Son of David have mercy on us (Mark 10:47).
Yet for all that James and John get wrong, they are correct in thinking that being at the right and left of Jesus is a good place to be. Mark later writes that with Jesus, "they crucified two robbers, one on his right and one on his left."
It is not an easy place, it is a place of death, but death with Jesus, the One who pays the ransom none of us can pay to God - the price of our life (Psalm 49:7). For taking what was not theirs, the robbers suffered justly. But in death, by grace, the penitent received what was not his, as Christ served him with the opening of Paradise.