I agree with you that a ban on assault rifles should happen, but I think you have to remember that the argument of the 2nd amendment supporters really has nothing to do with hunting or self-defense from burglars.
Their argument is that the 2nd amendment was written so that people's homes would not be defenseless from a military-style attack. Also so that the government would not be able to bully them. Basically so that people would be able to form small-scale militias.
In all likelihood, that actually was the intent of the 2nd amendment. The argument, IMHO, is whether or not the 2nd Amendment is appropriate in the 21st century, given the difference in deadliness between a muzzle-loading musket and an AR-15. All the laws written in the 18th century are not necessarily perfectly applicable today. That's why we have amendments, and judicial interpretation.