Read the victims’ accounts; Cheryl Yeoh has one on her website. She turned him down multiple times, and after each no he escalated his behavior instead of acting like a decent human being and backing off.
When you’re in a position of power over someone — for example, holding the purse-strings to a ton of investment funds — there’s no such thing as “just social, not work-related.” It’s no different than a boss propositioning an employee or a psychiatrist propositioning a client. Abuse of power isn’t limited to conference rooms or offices. Whether in a board room or a hotel room, if saying no means risking consequences that could severely damage your career (or, in Cheryl’s case, an entire nation of careers), or cause you to fear what the next step in escalation would be, it’s an abuse of power and obviously morally wrong.
It's a very basic fact of consent: if you are in a position of heavy influence or power over someone, free and equal consent is not possible.