German beer is typically various types of lager, with Kolsch and Altbier being the rather lager-like examples of ales in Germany.
Lagers are generally devoid of serious yeast-related flavors due to a combination of cooler fermentation (50 degrees F or so), and a long, cold (32 F) storage period (“lagern” in German means “to store” or “to store in a cool place”). Basically this puts the flavor emphasis on the ingredients, in other words, the malt, hops and water.
Most big American beers are lagers as well. However, they’re pale imitations (pun intended) of the original Czech and German lagers, such as Budweiser Budvar, and other Pilseners. In general, American beers are brewed from wort (water w/ malt & hops) with a specific gravity of 1.030 or so, while German ones are generally in the 1.050 range. This means that German beers will tend toward the fuller bodied and more alcoholic side of things, relative to American ones.
German beers are also traditionally all-malt. American lagers are typically 20-60% adjunct grains such as corn or rice, which lighten the flavor,body and color, while allowing the alcoholic strength to remain the same.
Finally, American lagers are hopped to a maximum of about 20 IBU (international bittering units; a brewing measure of bitterness), while the least bitter German beers start at about 20, and go as high as 35-40, in the case of Altbiers and some Pilseners. This is offset somewhat by the higher gravity and more intense malt flavor & sweetness present in some beers.
Basically, German beers are more intense in just about any flavor dimension you can choose. They’re not really any stronger in alcohol, but they’re more malty, more hoppy and have more body/mouthfeel than any of the Bud/Miller/Coors beers.
If the contestants don’t like beer, I can see how they wouldn’t like German ones, but only the most benighted of beer lovers don’t like German lagers. They’re some of the best made beers in the world, both stylistically and technically.