Well, in my case I became a Star Trek fan in 1986 (the only reason I know that is it was when I first saw TMP on VHS, which was a few months before TVH came out). My first actual exposure to anything regarding Roddenberry, the person, was in 1988 when I saw his introduction to "The Cage" when it came out on VHS. Before that, to me, his name was just another name on the credits. And I didn't learn much more about him until years later (probably around the time I learned about Richard Arnold's running interference for him on tie-ins since I'm a big Star Trek novel reader). And at that time it was about his handling of Star Trek affairs and his self inflated importance, things that just made him look like a pompous ass maybe, but not a predator. It was a few years before I started hearing about his alleged predations.
So by the time I had learned just what kind of man he was I had already invested years into Star Trek, bought countless movies, shows and books. And it'd be a hard thing just to shut off now admittedly.
If I knew way back when I started what I know now, I'm not sure I would have invested my time into Star Trek. I mean, if it was just the pompous ass stuff, his taking more credit than he deserves, that's not what I'd call a deal-killer. Let's face it. There's no shortage of self-important pompous asses in Hollywood. But the alleged sexual assault stuff just takes it to a whole other level.
I suppose in a way, the fact that it took so many other people to make his vision a reality makes it a bit easier I guess to separate. It probably would be harder if he really did have as huge a hand as he seemed to think he did in the day to day running of Star Trek.
I guess you can argue Star Trek is so far removed from Roddenberry's influence at this point that he's easier to ignore. Even going back to shows like Deep Space Nine and Voyager were pretty far removed from Roddenberry, since he was already out of the day to day picture by the end of season 2 of TNG and probably an in-name only executive producer after that.