Only some people used the effects of mental illness, in combination with much else, to justify official witch trials and similar State terrorism.
Mental illness is universal, official witch trials and similar State inquisitions not so.
The people hanged at Salem (not burned) were not, most of them, mentally ill. The relevant mental pathology would seem to be that of the accusers, interrogators, and executioners.
My guess would be that the incarcerations and interrogations of the accused would make a more profitable theatrical display than their trials - the circumstances under which almost all were brought to confession, and so many died before trial, strike me as likely to be more entertaining to the general body of fundamentalist Christians than the sober and public entering of pleas and pronouncements of sentence.
While they are at it, their recreation of a "first century ME village" also has possibilities known to attract money from the devout:
http://en.wikipedia.org/wiki/Sacred_prostitution