Let's have some devils advocate! Everybody loves devils advocate. Just real quick before I start cooking, I just want to say that rape is bad and there's no excuse. That's important and I'm not going to use it in my examples. Murder though - that's basically fine, I think.
A lot of crimes amount to one bad decision. A life of being a really good person and then one time you murder someone, then jail forever? (Well, yes, but actually no - first time offenders don't get life in prison, even for murder.)
Even if you have a dark side that you've been keeping under wraps, that's actually good! If there are people with dark sides, what we want is for them to not act on it - sociopaths, pedophiles - like, if we take for granted that these are conditions which occur in people and there's no cure, what we want is for them to not act on it.
But, one day, you fail, your dark side gets out and you do one of the horrible things you've been trying not to do; then it's easier to do it again, and again, and suddenly you're a serial killer. 40 years of being good despite a very difficult challenge, to suppress that darkness, but the rest of your life, you're judged for the few bad decisions you made in moments of weakness.
Let's talk about Ebeneezer Scrooge. Tis the season after all.
That dude was a total dick for like 60 years, but, in the end of the story, he's changed - it's a redemption story. But his name, Scrooge, is a commonplace synonym which characterizes him as a villain; fuck his redemption, he lived most of his life as a dick, and we remember him that way.
So which is it? Do we judge based on most of their lives, or do we judge based on a recent set of decisions which severely depart from that? Or do we just go with whichever was worst?
When it comes to Ashton Kutcher, like, even a serial killer isn't murdering literally every moment of their day. They have jobs, they go to the store. All that time, that person is being a good person, they're suppressing their darkness. It's easy to see a person in that light when that's how you've seen them for basically your entire adult life.
That said, Ashton Kutcher is a rich TV star so basically all his opinions are invalid. He probably only helps victims of sex trafficking because his PR team thought it would be a good fit for his brand. Not to say he doesn't like helping - I'm just saying fuck that guy. Fuck all those guys.