I only knew him a little. I remember his character and personality more than I remember any particular discussions.
I think the reason he left BKs was probably what you state. There's little room for a capable male to be in the spotlight much in the BKs. If they get into it, they're meant to turn it back onto the "Sisters". Maybe he did not do that?
I remember a number of the San Francisco BK men in the 1980s were upset about their talents and abilities being taken advantage of without proper application or recognition. That is, most of them were highly intelligent people who were basically treated as muscle and sources of funds. (As per the BK business model!!!)
Even though he was more "celebrated" than most, given quite a lot of regard in the global; BK community, it probably wasn't enough for him. As the BK system of evaluating a person's worth is based on a quantifiable status, a "number-wise spiritual hierarchy", it will only encourage ambition for status to be validated by explicit recognition.
And being an intelligent person (I am pretty sure he was a lawyer), he was obviously thinking a lot, spotting anomalies within the BK teachings and structure, and working stuff out for himself. I don't think he went straight from BKs into becoming a religion monger himself, but it must have one day occurred to him that he shouldn't deprive the world of his unique wisdom. Just like Baba

- bapsaman haha!!.
Then of course the imperatives of making a living and sustaining an ashram begin and become part of the play. So it all becomes more mercenary and personality cultish.
(As one of the essays of one of the many kundalini Yoga masters named Satyananda was titled - "Don't build ashrams!")