Humans are wired for pleasure. There must be some part of your binging that gives you a pleasure response, no matter how short lived. The aftermath isn't bad enough to overshadow the pleasure.
I quit drugs and alcohol at different times, and I just couldn't find the power and motivation to make sobriety stick for either one until the rush of the drugs was gone and there was no more warmth or happiness from the alcohol. In both cases the come downs and hangovers became so bad that thinking about using or drinking lost all appeal beyond chasing a high or buzz that died years before.