Exposure builds resilience. All shielding does is turn people into hysterics who cannot see through the artifice, and assume everyone is duped by it into being murderous zombies.
The news had actual blood on the streets, from real people who had actually died there, real violence, real panic, real bombs and real war. If you shut off the TV, it does not go away, it's taking place somewhere out there, in the real world. A game is a joke in comparison.