Because not all players realized the beating your spouse, baby mamma or children was wrong. I say if you really want to impact the culture, make it a "1 and done" policy. First offense draws a lifetime ban. Heck Pete Rose didn't physically hurt anyone and he's been an outcast for decades.
Clicky
The new measures include a more extensive list of prohibited conduct; independent investigative procedures; and a "baseline suspension of six games without pay for violations involving assault, battery, domestic violence, dating violence, child abuse, other forms of family violence, or sexual assault, with consideration given to possible mitigating or aggravating circumstances,"
Clicky