Same thing with all of the other people who were there reporting on the destruction.
Not necessarily. Some were sent on assignment. It's their job, and they don't really have much choice on whether they can go or not. They're drawing a paycheck, and that's a condition of their employment. One can argue that there's too many people reporting from Moore, and/or they may be getting in the way, or that they're soaking up too much of the resources which victims or rescue personnel could use.
But Beck is a media empire unto himself. And while that simple fact is disturbing in and off itself, that doesn't alter the fact that Beck could choose whether to go at this point in time or wait for a few weeks until the immediacy of the emergency is past. He certainly wasn't needed to pass out packages of food and other supplies.
IMHO, Beck is basically using the tragedy to build his image and further his professional interests.