I cannot express any opinion on the event at all. I haven't seen the performance. I know for sure that the message of the play was quite simple and obvious and was meant only to remind people of the tragedy and cause them to think about causes and effects. I don't believe the bloggers. Anything can be discredited and slandered. Years ago when I was a school boy, there ware lots of plays and other performances about the Great Patriotic War. The idiology was simple: children should remember the past and the heroic deeds of the Soviet people. Unfortunately, the case with this performace shows that it's not that simple to talk to young people from the stage. Do they actually care?

“If you want to draw people's attention, shock them!" It's a well-known rule. In this case the performance was successful – no matter what people think about it, whether they approve or disapprove of it, they do it. It's better to be blamed than to be ignored.
On the other hand, the moral aspect of the performance should be taken into consideration. What's the effect it produced? The idea was “to show that we all can fight terrorism only being together,” that's what the director of the school says. She also adds that “people didn't understand our message”. May be because they paid their attention only to HOW it was shown and not WHAT FOR?
By the way I think that the only people to blame or appreciate the performance are the ones it was performed for – the ones who have experienced Beslan tragedy. We can only express our opinion on the subject, they are to decide whether the performance was “a great mistake” or not.