Well intentioned? Maybe. Mostly it's nanny state in the extreme.
I think it's creepy. Way too Orwellian. Everyone always used to bitch about the GOP wanting to legislate what goes on in the bedrooms, now the Democrats are getting in on the act.
Rape is already crime, as it should be, and it is already prosecutable in California without this "affirmative" law. I expect that before a year is finished there will be many unintended consequences, but it's the sort of Pandora's Box that won't be easily closed once opened. Any legislator looking for its repeal will risk being labeled a knuckle-dragging misogynist.
This is what I was thinking. Rape allegations are oftentimes a "he said, she said" sort of thing, and particularly the kind of allegations this addresses. The main effect that I can see is that it would make it easier to get a conviction in absence of corroborating evidence, which makes my blood run cold. And Democrats complain that the courts have a conservative slant.