The other day, I mentioned to a new acquaintance my work as a TV critic for this magazine. I won’t elide the point: I was bragging. As sometimes happens, however, my boast spun around like a boomerang and knocked my teeth out. “There is much to criticize!” my friend replied with a laugh. That shut me up quickly enough, but it also captured the truths that make this corner of the reviewing business so thrilling and vexed.