This is pretty much based on the references to no fan interaction on the shows, not the actual incident, but I think when fans throw stuff at the ring, it adds something to the show. Like say when legacy does a beatdown of Cena in the near future, the fans throwing things at the ring (drinks, snacks, etc.) makes the act seem THAT much more appalling. If I was a heel wrestler, I'd encourage fans to throw stuff at me.
*Sigh* NWO/WCW days.