There were 17 tornadoes in SC on Saturday. There was a tornado watch in effect until 8:00am Sunday morning. The Club did the responsible thing by canceling the tournament due to the condition of the fields and the potential for more bad weather. Yes, the front hauled butt through the state and was gone Sunday morning. Nearly all of the fields were unplayable and remained closed for several more days.
If you want to play in soccer tournaments that are free from weather issues, move to San Diego. If you're going to live in the SE, you need to deal with the fact that it is always a crapshoot.
I don't know anything about the particulars of the Charleston event. I do know that it is never in the best interests of a club to cancel an event before it is completed. The decision is not taken lightly and usually involves hours of deliberations and consideration of alternatives. There are two factors - player safety and field protection, in that order. If anyone thinks that the clubs make more money by canceling, you would be wrong.