I tend to view the opposite. An individual is way easier to manipulate than an entire platform. Anybody who gets free products is immediately tainted. Project Farm says he pays for everything but all we have to trust that is his word. If you trust him, why don't you trust RT when they ban the company that paid for the reviews and say, "we take the integrity of our platform seriously"?

The more reviews that go into a rating, the more effort has to be made by bad actors to influence the score. And the higher the possibility that someone with integrity will reveal the scheme.