1. Since you read the post, I'm sure you noticed that scientists recommend doing a lot more than just banning AW. All banning assault weapons does is lower the number of people injured in a single incident and the severity of the injuries. The U.S. has another problem, it has more people on a percentage basis that are committing or attempting to commit violent acts. You can attempt to address the second problem by either preventing people from becoming violent ( e.g., better mental health services for children, more cooperative learning in the schools, helping parents to limit massive exposures to media violence, creating a less competitive/stressful/more help cooperative society), getting potentially violent people treatment (mental health screenings in schools, jobs) or (blocking potentially violent people from getting guns through background checks and more resources for law enforcement).
2. AWB not limited to rifles. Hunting rifles aren't assault weapons. Handguns can be assault weapons. Anything military is essentially an AW.
Which approaches are taken and which are not IMO tells you a lot about how much concern elected officials have about people's welfare.