My impression of how fire actions are supposed to work (at least in buildings such as this) is that the initial direction is for everyone to stay in their rooms. The premise being that:

a) The rooms should be a safe environmentt for a minimum of two hours and thus a safe place to stay with no risk of having to travel through potentially dangerous areas.
b) People travelling means opening up fire doors and stairwells thus aiding the fires ability to spread.

Then after qualified help has arrived and the situation assessed they can instigate an evacuation of areas (if required) where doing so will have no effect on the spread of the fire (those below the fire floor) and arrange the safest way of evacuating any danger areas (again if required), depending on the location of the fire and the buildings layout.

The idea of all the fire doors being to contain the fire and limit the amount of oxygen getting to the fire, and this being completely negated if people just evacuate with no form of control or direction.

Of course some places, with out such high standards of fire safety construction, the premises is "get the hell out of there as fast as possible". But if your being told for everyone to stay in your room I'm pretty sure the idea is to minimise the risk for all concerned as per the buildings fire plan.