That's because people are dumb and we live in an era where everyone is baselessly afraid of the social network zeitgeist. It's fucking pathetic, really.
Ray Rice's crime was between him and his wife and especially the cops. To the extent that he is s representative of the NFL a punishment is appropriate, 2 games was fine, 6 games would have been fine too.
What's not fine is a bunch of pathetic busybodies making it out like he murdered someone and stuffed her in his trunk. I get it, people are against domestic violence - do you want a fucking cookie? He should pay for his crime but "making an example" is rarely sound policy, and "listening to the rabble" is an even less sound policy.
I also like how the actual victim in this, his wife, is over it and married him afterwards but to "protect" her people want her husband to lose his source of income forever. Pretty sweet fucking logic, right there.