I also don't understand why they didn't just go with the popular Cirrus seat. By my count the seat density is only slight higher than the 77W (52 seats in 13 rows on 77W vs. 45 in 11+1 seat in row 6 on 777). They only get one extra seat in the new config vs. the Cirrus seat.
The Cirrus seat is really, IMO, the best business class in the sky. It is the perfect blend of privacy, space, comfort and layout. Just flew CX in the same seat and slept great.
I've flown the cirrus seat on CX and AA (A321T), I assume the 77W seat is pretty close. I guess I just dont' get it with this new seat, it doesn't look like it is pitched shorter than the 77W Cirrus seat, but you give up the shoulder room and storage space in exchange for having nothing above your feet instead of your feet in a cubby. Not a good trade IMO, but this is still an improvement over what was there before.
Even if the pitch is marginally shorter, having shorter pitch doesn't help until it adds up to a full row. Assuming around 45" pitch in J, you'd need to be 4" shorter than the cirrus seat to get an extra row. I doubt it is 4" shorter.