Burglar alarms are outside though, smoke alarms are in the room with you - or at least an adjacent one.
I can imagine plenty of situations where adults might expect to rely on older children waking to smoke alarms - adults with hearing or mobility impairments, for example. It also seems likely that residential institutions would have fire procedures that begin with "when you hear the alarm..." rather than designated adults waking all the children manually.
Anyway, this was brought to light by a friend of a friend with a faulty smoke alarm outside the kids' bedroom wondering why they hadn't woken up in the time it took to kill it...