This is gonna be the thread where we talk about stuff

All alcohol contains some degree of water (Even cleaning solvents rarely get above 70% ethanol) the presence of 4% ethanol is enough to eliminate a decent number of organisms that don't have the enzyme to break down alcohol.

The issue that people in that era often found, and many people today in poorly developed regions, is that the very sources for their water were contaminated. They figure dirty water is bad but sometimes they have very little choice. Finding clean water isnt as simple as "just boil it". Boiling water and storing it is really hard if you dont have the right resources. There are places worldwide that have to deal with cholera and other water-based diseases. Its a real problem.

Anyway, there is genetic evidence that there was significant selection pressures for those who could tolerate alcohol over those who could not in those regions. There is a nice research paper on the subject listed in the wiki article about alcohol tolerance.

Also I totes agree that people should still take responsibility for their actions while under the influence. It's why drunk driving is such an issue. I think few people actually blame their problems on the drink itself. If they do then there are other issues they need to deal with.