From what I have seen and heard from the mouth of Bankman, it does not seem that the whole idea about FTX was started to carry out a scam with premeditation, because he does not seem like a bad person to me, but just very incapable of keeping such a complex business under control. In the first interview he gave after the collapse, he admits that things would have been different if he had devoted at least one hour a day to that work (I'm paraphrasing from memory).
Therefore, he is guilty because he completely lost control, and in addition to his obvious incompetence, some of his co-workers also realized that they can do whatever they want because the boss does not supervise the work.
Such things should not be forgotten because people should learn from their mistakes and not pretend that it never happened. Although I think that for some new investors in a few years it will be just another in a series of bad stories from the crypto world, which will not affect their decisions too much - so it should not be ruled out that history will repeat itself when it comes to CEX.