No doubt the pros have learned more about tornadoes from this. I don't think this information is particularly useful or that it saves lives. We're talking about a force of nature here. All you need to know is take shelter. Nothing the storm chasers learn can prevent another or lessen its detsructiveness. Now we're hearing propaganda that guys running out there to confirm a tornado has actually touched down (as opposed to just spotted on radar) will get people to take shelter quicker. I'm not buying that; it's pure speculation.
As I said earlier, it shouldn't be prohibited. But if even one person caught outside on the road can't get to shelter because hundreds of storm chasers are blocking the way, then IMHO they should be held accountable.