Allow me to rephrase. Gibbon did a good thing by writing Decline and Fall. However, it became the be-all end-all discussion on the subject despite being 200-odd years old. We don't hold Elizabethan attitudes about any other aspect of sociology and history is being constantly revised, but European history remains "there were Romans, they were geniuses, then the Vandals came and it was all PURE DARKNESS EVERYWHERE IN THE WORLD FOR 1200 YEARS."
I honestly believe Americans and Europeans would be a lot more empathetic of the rest of the world if children were taught "and now we're going to cover that thousand years where we sucked bilgewater and the Muslims invented half the stuff we consider modern and preserved the rest from our syphilitic alcoholism."