Dr. John Mack came under attack by the Harvard establishment not because he dealt with the alien presence as a reality but because he dealt with it in a pro-alien manner. They are the good guys. They're here to help. Let's embrace them. Harvard, and its graduates, is tightly bound to the establishment, which hires them at prestigious salaries and contributes to the alma mater. The establishment, in sympathy with the New World Order crowd, wants the aliens to go away, or at a minimum for Earthlings to have nothing to do with them. They sought to punish Mack, by taking away his stripes and hitting him in the pocket book if possible, and almost succeeded. Publicity on their secret hearings forced the proceedings to stop, as the alternative was to dress their mean motives in angelic clothing, and this proved to be an impossible task.
Was Dr. John Mack accurate in his conclusions, and were any of the accusations thrown his way valid? He chose to give the benefit of the doubt to benevolent alien intentions, rather than malevolent intentions, where other therapists went to the other extreme or remained neutral. As there are two orientations visiting Earth, all good or all bad interpretations are of course incorrect. However, therapists who give the benefit of the doubt to malevolent alien intentions don't come under attack by the establishment as Dr. John Mack did.