That interview posted is interesting in exactly what she says.
Obviously, it's been 25 years, she's long over any mistreatment she received on the set and doesn't want to trash anyone. So she has vague fond memories of everyone then she trashes Paramount and 'Creativity'.
Ask a majority of Trek fans, season 3 is when the show picked up, when it got much more creative, so even if Paramount didn't have the same creative drive as Gene Roddenberry, they clearly hired a bunch of people who did. It seems like Diane is almost revising her reasons for leaving as a creative difference, romaniticizing Gene Roddenberry's influence even while claiming not to have ever seen the first season when his influence was at its strongest.
I don't know what really happened between Diane and the other cast, but 25 years past she's sunk into politic mode.
Edit: Wait wait wait. Wasn't season two the season where the writers went on strike and they reused a lot of Star Trek: The Second Wave scripts? Creativity my butt.