I disagree that incendiary bombs were designed to 'deal' with civilians. Incendiary devices were used during strategic bombing raids by the Luftwaffe and the RAF in the west, and the USAAF in Japan in order to de-house the population and destroy buildings. If you read the quote from Air marshall Harris in your link, you will see that the British observed the devastating results in the Luftwaffe raid on Coventry, where high explosives were mixed with incendiary bombs, and decided to use the strategy during RAF raids in Germany, not in an anti-personnel role, although many, many civilians died, but as a way of destroying factories and warehouses, and the de-housing of the working population.
Who is your initial quote by?