I was just looking through the NHC gold medal recipes in Zymurgy, and I noticed that of the 23 gold medals for beer:
15 were single infusion mashes (with and without mashouts);
4 were multi-step mashes; and
4 were decoction mashes.
Included in the single infusion mash category were such styles as Vienna Lager, Schwarzbier, Bock, Cream Ale, and Dusseldorf Alt.
I'm not knocking step mashing or decoction mashing (they both obviously have their place), but that's a pretty strong showing for the single infusion mash.