Ask HN: Is an objective and profitable review site possible?

My father is an expert in an industry that 95% of Americans consume from, but know very little about. He currently runs a fairly popular blog where he gives advice and answers questions. I've discussed ways he could monetize it, but he says that he enjoys helping people and if he were to accept sponsorships or affiliate programs he would stop being objective and wouldn't want to do the work anymore.

Even if he ran banner ads, he wouldn't want them to be for products he wouldn't personally recommend.

Have you solved this problem or seen it solved in a review site that you use?