A room is protected by a glyph of warding. To pass through it, a phrase must be spoken. Does each character that wishes to pass through have to speak the phrase if they are in a group?
The spell has a way to bypass it without setting it off. If you could key it to a whole room then everyone would have to say the password. Better to key it to a doorway that way only one person has to say the password to open the door. The rest can just enter.