Matt Groening’s cartoon family has made the grade as cultural icons for the current generation. Bart Simpson’s “Cowabunga!” and Homer’s frustrated “D’oh!” sum up two personalities we can all relate to. The Fox series makes wry observations on all manner of current fads and foibles affecting American life. In short, the Simpsons — like all great cartoon characters — are a reflection of our people and society at the time. And merchandise and licensing based on the dysfunctional family rang up unprecedented numbers. Skein — which launched in 1989 — helped Fox become a real network.