Every time someone asks me for a kit recommendation I point them towards some sort of prime lens with a standard focal length. Similarly, almost anyone I talk to about the ideal budget kit swears that fixed lenses get much better quality photographs than similarly priced zoom lenses.
What factors contributed to the revolution of the default 'kit' lens changing from a 50mm prime to a zoom lens in consumer and prosumer grade cameras. Why wasn't the 50mm replaced by the 35mm lens, which would be standard on a crop sensor? I am interested to know from a manufacturing and distribution point of view why broad range variable zoom lenses replaced the default SLR lens.