Sudz - Excellent post. Thanks! I never knew about the four factors...
1) Popular backlash against anything German during WWI
2) Prohibition soon put many of the smaller breweries out of business
3) During WWII, the beer companies caterered more to women clientelle (the men were overseas) who wanted a lighter, less full-bodied beer
4) The rampant capitalism during the 50s, 60s, and 70s led to cheaper industry processes for more profit (more rice, carbonation, tins).
But reading your post, that made perfect sense.
BUG_EAF - yes I was at Eurocon2000. It was late in the year and there was no Eurocon2001, but I went to Eurocon2002 and will go again to EuroCon2003.