Rossoneri,
That is quite an astounding figure for one airline at one airport, especially considering the cost-reduction drivers coming from the EU. NATS started its environmental thing way back in 2007 I think, and this system certainly flies in the face of that strategy. A holding area flown by a stack of modern FMS aircraft is fairly compact too.
I remember an article in 'Transmit' magazine called "De-skilling the profession" years ago, around the turn of the millennium possibly.