To limit the probability that an unexpected discontinuity of handrails will lead to an interruption of the user's hold on the handrail, which could lead to falls, which could lead to harm to persons.
To limit the probability that an unexpected discontinuity of handrails will lead to an interruption of the user's hold on the handrail, which could lead to inefficient movement in an emergency situation, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.