He's not saying that they shouldn't be subject to coverage "with an investigative lens." He's talking about the adversarial, negative tone of the coverage, relating to the tech industry primarily as full of bad actors rather than a power center worthy of investigation that also does some good things, say. I don't think Yglesias would say we shouldn't investigate these companies, but rather that we should paint a more wholistic picture about both the good and bad contributions of these companies that better matches reality.