I'm fine with the six game suspension. Especially since I just learned that it's adjustable downward or upward, based on circumstance. That seems to be about right for me, assuming the evidence is there as is the case with Ray Rice.
Having said that, there are a ton of issues with the NFL being judge, jury, and executioner. What if a scenario such as the one BradyFTW! laid out comes to fruition? What if a guy is in a relationship with a psychopath and gets falsly accused? Are you going to ban him for life the second time it happens? The NFL should let a court of law decide a man's guilt first (as is the case with most of the other institutions in this country) before deciding a player's fate. After all, not every case is going to be as cut and dry as Ray Rice's where there is video evidence of him dragging her unconscious body out of an elevator.
Futher, is a lifetime ban really going to prevent the cases of domestic abuse that DO happen? Is a woman going to report her husband/boyfriend the second time around knowing full well his career (not to mention millions of dollars) would probably be lost if she follows through? Is she going to bite the hand that feeds her? Probably not, as we've seen in a lot of domestic violence examples. Once again, Goodell is too broadly reaching on an issue. That's been a staple of the Goodell Error.