To limit the probability that a fire involving a service room will spread into the exit, which could lead to delays or ineffectiveness in fire emergency response operations, which could lead to the further spread of fire, which could lead to damage to the building.
To limit the probability that outside venting of a service room for fuel-fired appliances will lead to a negative pressure in the exit and draw in products of combustion from other spaces, which could lead to delays or ineffectiveness in fire emergency response operations, which could lead to the spread of fire, which could lead to damage to the building.