However, such weapons are quite fun to shoot, are robust and reliable, and are quite versatile. They are also lightweight and easy to use and train on. Plus, the ammo is relatively inexpensive.
Not to mention they are also very 'modular' in their design, very easy to modify (simple to build an entire gun from a bag of parts using a few simple tools), very easy to swap uppers (thereby facilitating caliber changes) and lowers, lots of aftermarket parts available, and they represent the current "state of the art" in homeland defense, tyranny-busting, Constitutional Militia arms. Other than that, no one "needs" such a weapon, unless one takes the 2nd (or the Constitution) seriously and believes the Founders' words (paraphrased as:"the Right to Keep and Bear Arms is the bedrock of liberty."