Its just this big incident this year. Last year we had Jonathon martin and Incognito, 2012 - bounty gate, 2011-lockout, etc. Its an unfortunate pairing of events that the simple minded media like to make big deals out of and the NFL goes on a witch hunt to try to clean up their image. Nothing new, this happens in most popular sports.
It's more of a snow ball effect. The Ray Rice incident happened months ago, April if I remember correctly. NO ONE was talking about it in the months that followed. He just got a slap on the wrist with a two game suspension, and people where happy. It's not until recently, that the video surfaced where we saw him punching his fiance, that people demand that he get a more hard penalty and accused the NFL of mishandling the situation. Since the topic was being covered by more media stations, other incidents like the Dwyer and Hardy had risen up. Because the NFL "mishandled" the Ray Rice situation, they can't let any other incidents damage their image. Honestly I just feel the league is making up the rules as they go along. Just take a look at the Peterson case. That's another one that I feel the NFL is just throwing darts and seeing where it lands.