It moves hand in hand with the cultural perception that alcohol consumption is madatory if people are to enjoy themselves.
Sadly, we encourage the shyness and insecurity of adolescence, when some numbking alcohol takes the edge of insecurity and paranoia, and carry it on into adulthood, where only by drinking is a person able to relax and have a good time.
It reaches a stage where - as you have discovered - if there is a chance of that crutch being removed, some people would seriously rather not attend an event at all than attend it without alcohol.
That cultural perception is the reason why we have a drinking culture - and why the notion of a 'cafe society' was always doomed to fail.
the British don't drink because they enjoy the taste of nice wine or good beer, they drink because they need the anaesthetic effects of alcohol to a greater or lesser degree.
When we can educate a generation of childen that alcohol poisoning is not a good barometer of a pleasureable evening, we will be on the way to phasing out the mass of crime, damage and misery caused by this insidious drug.