Was this even necessary?
1- Freshness. The timing of my travels and the rebirth of California Adventure means I haven't seen it during the Christmas season. That alone is a big draw. What music do they play? What special treats are available? What's the entertainment like? The decor? As much as I hate to admit it, Disneyland is feeling old these days.
3- Crowds. Yep, they will be there, that's a given. However, nothing can be worse than the "Small World Crush" of crowds after the parade. It should be illegal from a safety standpoint. If there was ever a fire, some people would not be able to leave safely.
(Photos copyright the excellent Magic Eye website.)