I think that saying is one of the dumbest defenses ever, and I am sick and tired of people using it.
Since this is a skiing website, I'll use the old skiing vs snowboarding "rivalry" as my example.
"park skiing wouldn't exist without snowboarding" which goes to: "snowboarding wouldn't exist without skiing", so I guess the next one would be "skiing wouldn't exist without, shit I don't know - the need for easy transportation in the winter?"
bottom line, the saying is really dumb and annoying as hell, because what it eventually all comes down to is this "without anything we'd still be sitting in a dark cave grunting to each other.
snow wouldn't exist without winter, so what's the fucking point.