It depends on how hard you run them. If you really run your AR, and not only shoot a few "hundred rounds at your range without a hiccup", only a few ones will survive trough anything you throw at them: Colt, LMT, BCM, Noveske, the chart is there to help you. And I'm talking only about complete AR's from the factory.
If you build your AR-15 yourself, you can build an extremely dependable AR (equal to Colt, for example) by choosing quality key components, such as the BCG and the barrel. The major brands that make quality components that will not fail, are LMT, BCM, Colt (if you can get the parts), or Charles Daily and such, Daniel Defense and such, and that's pretty much it. The reason is that they are are tested and inspected individually (test fired, Shot Peened, MP Inspected, have the right military specs, etc), and the parts that are not perfect don't get out of the factory,
Every AR will go bang, it's a proven fact, but not every AR will survive the shits and still go bang when you pull the boom switch, especially if the major components are not the highest quality (BCG and barrel.)
I will get all sorts of replys for this, and that can only mean one thing, I hurt their feelings right in the nutz.