Alcohol damages the brain in a several different ways:I would guess that it's just random. But you never know, the alcohol might even be more attracted to more active synapses.
The worst is the permanent memory damage caused by thiamine deficiency in long term, heavy drinkers. Wernicke–Korsakoff Syndrome is outright debilitating, and its sufferers have to be institutionalized.
If you google "alcohol brain cells" or "alcohol brain damage" you'll find all aspects of alcohol's effect on the brain are constantly being studied and it's not random.
Brain cell damage aside, it should be obvious to anyone who has ever been even slightly drunk that the slowed, sloppy, emotional thinking that results is counter productive to a rigorous mental activity like physics. The hangovers are equally counterproductive. Had Feynman not put the brakes on his increasing temptation to spend his time drinking he might very well have stalled his carrear, or have sent it into a descending spiral ending in a crash.