Frankly, Richard Arnold's reign seems to have been the TrekLit equivillant of the Hays Code.
But to be fair to Arnold...a lot of the blame seems to be Gene's, with his obsession that no writer DARE show Kirk & Co., Starfleet, or the UFP in any kind of internal conflict.
One need only read his biography...and the chapter on the novels. Particularly telling is Gene's letter regarding a novel which he claims paints Starfleet in a far too negative light--apparently Prime Directive
. He claims that no matter how bad the situation was, Starfleet would NEVER hold Kirk in disgrace, like that!