The "assault weapons" argument is one of the more egregious ones made in this document.
"Military=style" could apply to just about any firearm, as most firearms have been used by the military at one time or another.
An important distinction is "semi-automatic", which the author acknowledges. These are CIVILIAN versions of rifles that were originally designed and made for the armed forces.
They are only "incredibly destructive" when used for criminal purposes. Otherwise they offer a lot of features civilian sportspeople like myself enjoy.
Why do I like them?
Easy to shoot
Modular, allowing for customization according to my shooting preferences
Adjustable stock allows people of different statures to use the firearm
Highly accurate
Easy to disassemble and reassemble for cleaning and maintenance
There are probably a lot of other reasons why people like them. It is a fact that the AR-15 is the most popular firearm in America.