Fails at activating as many motor neurons as possible in the muscle, versus full ROM. Full ROM lifting activates more motor neurons than shortened ROM.
The point of lifting is to activate motor neurons, and recruit fibers. Recruiting as many fibers (all or nothing principle) as possible provides greatest stimulus across the muscle, providing greatest potential for hypertrophy. It's also superior for strength athletes who depend on the ability to maximally recruit all motor neurons on a 1RM lift to ensure success on a lift.
Sometimes you want specific motor neurons activated (working around injury, addressing weakness, other...), and that's where ROM-compromised lifts serve a purpose (like floor presses). But most of the time, you probably don't want a shortened ROM.
Too much time spent lifting in a shortened ROM can actually also potentiate injury. A less flexible muscle has a naturally shortened everyday ROM, and is more prone to tears. You can get around this with more flexibility training (i.e. stretching, yoga, deep tissue massage (no t-bombz), and active release and foam rolling). And with pre-workout activation work.
sorry, not correct. the neurons are recruited in response to the effort required- which is partly learning the movement and the rest in total effort (intensity).
full ROM has nothing to do with recruitment. The only reason why additional neurological activity would occur would be due to more muscle groups being involved...other than the focus, or target group. For the target group, the ROM and motor activity are not related (at least for half to 2/3 reps (im pre empting those clowns who try to argue about 1/10th reps )).