The “fear” theory is troubled with evidence. Both Collins, Keller, and Ken are have been wrestling with this for years. They have not ignored the evidence, but have been trying to piece things together. Fearful people do not engage as deeply as have these three.
Instead, we could just take them at their word. They say it is a matter if integrity for them. I see no reason to doubt this. In fact, it makes much more sense of their behavior and their history.