That’s because this isn’t a court of criminal law, but a court of opinion in a very tight-knit professional field where everyone more or less has to work with everyone else, and some people have disproportionate amounts of clout which means that you have to work with them if you want to work at all.
Women who accuse powerful men of sexual assault have to push through a lot of barriers, both internal and external. They have to overcome their own personal feelings of shame and doubt, and then weather a storm of abuse because the general public tends to be more willing to side with a famous person being accused, especially if they’re a person with a fanatical following (see: Julian Assange, or Bill Clinton for that matter). If someone is fully cognizant of that, or worse, has had their career or public life directly threatened to keep quiet, then going public with those accusations is a massive gamble which the victim has considered a big enough price to pay if it means getting the news out.
In an industry like film, that’s of huge importance too. As mentioned before, Hollywood is pretty tight-knit. If you piss off the wrong person, they can ruin your career, and film shoots mean that you can spend months or years in the power of another human being. If there is the non-negligible chance that one of those people is capable of sexual assault or abuse, it should be known, for the sake of the people who have to work with them if nothing else. None of this involves legal procedure, and none of this involves a court of law, where “innocent until proven guilty” remains the precedent. This isn’t about crime so much as it is about risk, in an industry where the abused tend to be in the most possible danger.