Personally, I will say that I liked what of Neil Gaiman I knew. He took me in, if one can say that. I'm not sure, honestly. There will be people who say that he was playing a feminist and a nice guy to fool people, to make it easier to be monstrous behind the scenes, but if so, he played the part extremely well. At some point it will probably come out that he's stopped pretending and has shown his true colors. Scratch him and maybe he'll bleed fascist, for instance
But there's always the chance that he contains multitudes. How can he rationalize his private actions with his public statements? People are good at rationalization. If he's simply a soulless pursuer of power, he'll jump ship to whatever will get him that, but as hard as it may be to admit, there are plenty of people who truly believe that they're good people, truly believe their statements which we understand to be good, and yet are flawed? That seems dismissive. They're not good people, but they're not entirely bad?
Gaiman's sexual proclivities might be entirely squared in his mind with feminism. After all, feminism is about a woman's right to choose, and he may think that these women chose. I won't go into details here; you can read about them easily if you want. But a failure to understand consent isn't unique to awful people, and a failure to understand power imbalances isn't either. Maybe Gaiman genuinely thinks that he's done nothing wrong. Maybe he feels bad that these women obviously didn't have a good time, but that's the end of it.
That in no way excuses his actions. Period, full stop. But it might explain the trajectory. And it might explain how he could have been so convincing. I say all this not to make you feel better about him but about yourself if you feel taken in by him. You weren't a sucker. It's not your fault.
But it's just as likely that he was just a really good liar. The Scientology stuff, which hasn't been as widely circulated, suggests a more sinister Neil Gaiman. And that's not your fault either.
I suspect that it's a mixture of the two, really. He can contain multitudes, and some of them can be horrible. I was taken in. I can't help but feel a little bad about that, but such is life.