I've read of a few cases at various places where academic redshirting was an issue. The parent would complain that the child was bored, the teacher would look at the child's file and notice the child should be in 1st grade rather than K. A friend held her DD back b/c w/ an August bday, she'd be the youngest by several months due to wide-scale red-shirting. Parents are basically balancing the more academic nature of K compared to a few years ago, by delaying entry into K.