Funny! But kevlar is good for protecting you from sharp impacts. A helmet is more to cushion shocks to your brain in relation to your skull. I don’t think kevlar will do that.
Understanding that it’s mandatory service for most everyone, how does that make them different from other soldiers in combat? It’s like full-time firefighters vs. volunteer firefighters. Their mental approach to the job may be very different, but when they’re fighting a fire (or fighting in Lebanon) they’re not so different.
They don’t want you to get injured or killed for the “wrong” reasons. 