Because its hard as hell to keep an idle when driving normally. Its murder on the clutch keeping an idle at stop signs and lights.
Why would it be murder on the clutch at IDLE? Unless you meant murder on the clutch when taknig off from a stand still, which isn’t idle then.
Well, Yeah. Thats what I meant. A buddy of mine had them on his GSR and they were cool and all except when we would go out daily driving. He had to get his E-Brake technique down pretty good.
At a stop sign:
Clutch in, tap on brake, then tap on gas to keep idle while holding e-brake. Shift into 1st. I think you get the picture.
if he had to tap on the gas to keep it on, than he was either not tuned for it or his timing was way off. weird
You got it 
Although tuning the idle on these cams would definantly not be easy, but it is fully doable where any amounts of load at a low RPM would not effect the idle.
Well, I guess you could say its a mixture of both. Timing and Tuning. But still, those cams arent that easy to handle if your unexperienced. Agreed?