To set the latest acqua alta situation in its right frame, there was a big storm that hit most of Italy, leading to lots of damages all over the peninsula and a number of fatalities (>10). Trees fell down, rivers flooded, mud slides occurred, and Venice was hit by "only" a bigger flood that "usual". At situations like that in all of the country most people tried to stay inside, and not only people affected by acqua alsta in Venice. My "point" is that throughout the world (very) bad weather that can't be predicted months ahead can create big problems to tourists, since they are usually visiting a place within a pre-determined period of time. Avoiding Venice on December 25 because there was a big storm in late October is sort of illogical!