What the presenters could do ( and get away with ! ) and what the presenters CHOOSE to do, are 2 different things. If Q allow DF to be so self promoting, self adoring and self important, then yes I daresay others could do it too but they choose not to. I guess what`s acceptable behaviour to one presenter, is unacceptable to another and different personalities behave in different ways, such as we all do.
DF sees herself as not only being the centre of her own World but also wishes to be centre of other peoples Worlds, she longs to be liked, loved and adored and some people are daft enough to do it. That`s their choice but it isn`t my choice.