Validating Scientology is the unintended outcome of entertainment projects designed to hold the beliefs of the church up to ridicule. The church can indeed be legitimately criticized and effectively marginalized, by exposing it as a more-or-less criminalized cult. But trying to take them down because their beliefs seem silly, ludicrous or outlandish, is unlikely to be an effective tactic. Potentially, that could even backfire.
First of all, the beliefs of well-established religions, and often enough the beliefs of individuals who are not religious, are also commonly easy to mock. The beliefs of big-time religions, and of non-religious organizations and persons, are routinely subject to ridicule. Beliefs of others have been favorite objects of mockery for centuries & millennia, all to little or no avail.
Possibly a more likely account of projects like the movie Going Clear, and the South Park episode to which it bears a suspiciously strong resemblence, is that