There is an awful lot of grass is greener going on. But a fair number of those same students are back home at the community college by second semester, or at whatever home state public will accept them by the second year. Grade and money problems can change things drastically.
Be realistic with your DC about your budget, and be clear about your expectations for grades/major/time-to-finish. If you need your kid to stay in state, then let your kid know that.