Since you can "pull the trigger" on most of those weapons just as fast as you can read the line above aloud, it is still a pretty effective weapon. I fail to see why anyone outside the police force or military needs one. Deer don't usually wait for shots 2-7. *IF*, as Steve suggests, it is just 'fun' to go out in the desert and blast some innocent cactus, I still don't see why anyone needs one. The answer, obviously, is not 'need', but wishing to have them and wishing to interpret current law to allow them to have such weapons. The world is full of folks who want definitions to be interpreted to fit their own desires and interests....that's why lawyers make a lot of money arguing the details.
As Mick says, I don't really expect much to change in those laws very soon........but neither do expect a big decline in sad headlines.