One of my classes at uni taught me that doing drugs (especially alcohol) is sometimes necessary for getting things done, but I still wish this wasn't the case.
Pure curiosity.
The reason why alcohol culture frustrates me is that in high school, I had an older friend who started going to AA and brought me along for moral support sometimes. I've since grown up, developed a fondness for craft cider, and realized that I personally don't have much to worry about from addiction. But for the same reason I think startup events should be expected to be wheelchair-accessible, I think folks should be cool with teetotalers.
Interestingly I read an article (perhaps it was posted here?) in recent days about westerners struggling in Japan and one key point was the expectation to go out drinking heavily after work every night.
I can see the merit in holding networking events surrounding drinking as alcohol will (perhaps) get people to put their guard down, relax and socialise more than if everyone were stone cold sober.
I will be interested to see what happens with regards to marijuana and networking events. Though the moral argument against marijuana is gone, there is still a stigma associated with the drug. In many professional circles cocaine is currently more likely to be the accepted drug of choice than marijuana (going by personal experience).
Marijuana is also different to alcohol in that one can have a few drinks over a reasonable amount of time and be more relaxed without getting intoxicated, however a few drags on a pipe with reasonable marijuana in it will cause rapid intoxication. How well that bears for networking events is something I'll certainly be interested to see!