Why do the patients in the hospital cause John to shudder when he looks at them?

The hospital patients in Brave New World cause John to react this way due to the clinical, unemotional setting in which they rapidly head toward death under the influence of soma. Death is treated casually and cheerfully in this world, while John's limited experiences and emotional development, combined with his exposure to intense emotions and tragic moving death scenes via the works of Shakespeare, inspire in him high expectations of what his mother's death should entail. John wants to vividly feel love for her and heavily experience the impending loss: an ideal completely at odds with the scene unfolding around him in which Delta children are desensitized to death at a young age so that they will never fear or be moved by it. This childhood indoctrination is repugnant to John, as is the matter-of-fact manner in which the children and nurse accept his mother's passing.