From a policy point of view: More people theoretically involved and can be harmed, both on board and on the ground. Much higher energies involved which increases the damage caused.
And of course the conclusion that we cannot point to massive numbers of deaths due to drinking in aviation, has to do with both a quite heavy policing of alcohol use in aviation, and very low accident numbers in general. However, there are some cases where alcohol use was at least mentioned as one possible part of the problem, like for example in the case of Aeroflot 821.