Yes, water dowsing is bullshit, and that has broad consensus. So, the author uses that to basically make the argument that journalism should no longer be objective (the current prevailing trend amongst journalists, it seems), and to report only the "truth" that the reporter believes in. This is why "journalism" is crap nowadays, and why so many people have lost faith in it. Because, writing about Covid's possible lab leak, or wondering about the new vaccines are really similar to writing about water dowsing, right?

It's classic Strawman arguing (and even has a Trump reference for a bonus point).