There is a compelling reason for the fore and aft motion of the 222's collective pitch that vastly outweighs the pilot preference - collective bounce.
My guess is that the 2 bladed rotor on the original 222 is of the family that has a significant "bounce mode" where the natural frequency of the collective pitch system (mainly in the rotor head) is very low, and naturally tunes to the pilot's arm/hand frequency. This is quelled on the AH-1G with a friction collet that clamps the collective to the main shaft and forces the servos to fight the friction. The friction strongly damps the collective bounce, but it adds weight, complexity and requires stronger servos than otherwise needed. A big contributer to the collective bounce propensity is the pilot's motions that get amplified by the rotor's natural frequency.
The novel collective pitch lever that has no up/down motion is a wise solution to the pilot end of the problem, IMHO.