The seatpockets/ privacy screen are so high because to seat slides down forward instead of moving back. It gives the passengers behind you more space left when you want to sleep & the passenger behind you doesn´t ..
The seats as used by CX
and others take away the space in front of you even more because the seat back is hard top & fixed, even if the passenger in front of you is inhe upright position.
View Large View Medium
Photo © Bailey
Also all the big screens flickering in the dark on the high fixed seatbacks can give a Las Vegas like look to the cabin, many passengers don´t like that all night...
The KLM/CO seat´ sleeping comfort is the same (it can go flat under a small angle). You have more living space left during day time (and then is when you need it.)
About the 2-3-2, the seats are as wide as on a 2-2-2 Airbus. The load factor in business is on average 60-70%. The seat are empty most of the times. Aisle passenger love the free middle seat next to them ...