Streaking near a playground without knowing of it and threatening to rape someone's daughter are completely different things. Telling anyone that they want their daughter to bleed into their underwear because you raped them is sickening, intimidating and frankly sexual violence.
Hold your horses. There are many crimes that don't put people on a life-ruining sexual predator list. Murder for example. That doesn't make them 'acceptable'.
I don't think this crime should go on that special list. I think a reasonable maximum for this crime is a few months in prison, similar to misdemeanor battery.
I don't think the register is justifiable at all, to be honest. We don't have it where I live (Australia) and we don't have higher levels of sexual assault than the U.S. (our rates are still too high).
If that was the point you were making, I apologise as I misunderstood you.
Since when did this become acceptable?