Some states can restrict them more, some less. You do bring up a valid question. One where the answer "recreation" or "freedom" isn't an answer that will satisfy everyone. But I do wish to make a few more comments on this.
First, as known, not all weapons are able to purchase, some are limited. Automatic weapons, flame throwers, grenade launchers, etc. So an argument could be made that semi-automatic assault weapons belongs in this category. But at the same time, some argue that automatic weapons should be legalized.
Next, as I noted a few pages back, you could ban these weapons, and not only would it take a few decades to get
most of them out of society, it still would not stop someone determined to kill a lot of people. Home made bombs work pretty well for that. Imagine if Holmes had locked the emergency exits in the theater, set the place on fire and blown it up.
Third, I will stress once again, this is a social issue more than anything else. we live in a society where people with problems are too often ignored and pushed aside. There's also economic issues. Blame who you wish for this, and I blame both political parties, but when a PhD student is finding no work in his field and instead working at McDonalds...
This is true, sadly. But because a lot of people were shot at once, it gets a lot of press. A few here, a few there, no one takes much notice. In 2007 for example, 12,632 were shot and killed by hand guns (homicide). As you likely guessed, most of these people were impoverished, living with little social support in economically depressed areas.
The chart below is very telling. It shows gun deaths by type in the US, by year. What's most significant is that if you flip the chart upside down, it becomes a chart of economic growth and prosperity in the US for those exact same years.