From what I understand the 45 degree inclination of the flybar is to counteract the fact that the swashplate tilts forward/left in 45 degrees when the cyclic input is "straight forward".
Apparently, the 45 offset of the flybar will counteract this and produce the resulting force that drives the chopper approximately straight forward.

One advantage with this setup is it's simplicity. Only two servos required. Cheaper to produce and consume.


Biker-74