Her ruling is full of inconsistencies and errors and I'll let you read the article for an analysis of many of them, but the one that struck me was her claim that they are unsuitable for self defense. Well, other than her unsupported argument that the Second Amendment was written to protect the right of self defense, she also states:
As for their claims that assault weapons are well-suited for self-defense, the plaintiffs proffer no evidence beyond their desire to possess assault weapons for self-defense in the homeMay I refer you to the Federal Government which published a bid request for a "personal defense weapon" capable of select fire (single shot or automatic), firing a 5.56 x 45mm round (M-16 round in case you aren't familiar with them), and utilizing M-16 magazines. In other words, they wanted to buy a whole bunch of M-16 style weapons, military grade, for the specific purpose of "personal defense".
DHS and its components have a requirement for a 5.56x45mm NATO, select-fire firearm
suitable for personal defense use in close quarters and/or when maximum concealment is required.
Personal Defense Weapons Solicitation HSCEMS-12-R-00011
Suitable for personal defense in the hands of the federal government but not in the hands of civilians. Might I remind any skeptical readers that the Second Amendment to the Constitution protects the rights of the people, not the rights of the government.