The reason that the majority of sexual assault cases are either never prosecuted or fail to get a guilty verdict is usually because it is felt that there isn't powerful enough evidence and the alleged victim's account can be seriously undermined. Generally speaking, people do not have sex in public and therefore there must be overwhelmingly compelling evidence for a guilty verdict to be returned.
If a Hollywood actress decided to make an allegation of sexual assault or harassment, presumably she would put herself at risk of being sued for slander. If she lost the case, she would be persona non grata, branded a liar and undoubtedly her career would be over. To make such an allegation, as Ashley Judd did, was therefore a huge risk and one that many women would be too afraid to take, particularly if they had, in the past, made a tentative complaint to senior figures in the industry, or the police, and had been rebuffed.
There may well have been some women who did not object to this man's attentions or who willingly had sex with him, but if there were any women who experienced any sort of sexual harassment or assault and who felt frightened and intimidated by this man - or any other powerful man in the film industry - a crime had been committed against them and the fact that other women might have consented is totally irrelevant.