Wirelessly posted (8700g: BlackBerry8700/4.2.1 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/100)

My opinion: The reason is that it is assumed if you enter a calendar event it is a true event. If the time or date changes, then you edit the entry, not snooze it. Just my opinion.

Same for tasks. You enter a tasks because it is a real task an you need to drop what you are doing and take care of the task. If you can't drop what you are doing that second, you snooze the task and wrap up what you are doing ASAP. My opinion.