That's what I thought when I first purchased my vehicle (with iStop) however it doesn't bother me at all now.
You can also turn iStop off (must be done at each start) but the real trick is to learn that if you don't apply too much brake pressure at ltraffic lights, iStop also doesn't engage (ie only keep the brake depressed just firm enough to stop vehicle movement).
The restart is also very quick so it barely makes any difference when moving off from the lights. By the time you move your foot from the brake to the accelator, the motor is already running.
