A remote control has an infrared LED through which quite a lot of current is pushed through, 0.5-1A in short pulses and bursts. The internal resistance of alkaline batteries is quite high and gets higher when the batteries become empty. The currents through the LED causes the voltage to drop too much, likely below the lower limit of the other electronics in the R/C.
NiCD rechargable batteries have a low resistance during most of their useful charge, and are better suited to high current applications like electric drills.
Jeroen