"To be (instructed) or not to be (instructed)" is that really a question? Hamlet pondered a more serious subject with that great, dramatic line but students address this issue all the time when asked "which afterschool program would you like to take this semester?" Whether it's an afterschool, lunch club, or camp, students usually choose the one that they feel will be the most fun, not the most instructional.
Most chess camp and afterschool chess programs suffer from their own ambition, to instruct players and help them improve, or let them just play and be happy?! The general cut-off for instruction vs. playing time is around 30-40% but when the lessons get too long, enrollment drops. Then again, if there is no demo (demonstration instruction) time, the students get bored and have no sense of progress and move on to other things.
It's a tough delimma but most of the dedicated and academically minded students and parents know what is best ... the rest will pay more attention to whether they can bring their DS or Nintendo.