Nobody is saying acetaminophen is ineffective, just that it's effects come with hepatotoxicity. A larger dosage of hydrocodone could have the same net analgesic effect without the huge negative effects.
Actually, the linked article is saying exactly that:
"I remember being annoyed that in order to get narcotic pain relief I was being forced to take a hepatotoxin that added little to the pain relieving efficacy of the opiate."
It's not like he did an n=1 study. He just assumed it wasn't going to work for him. My impression of the article, given that it doesn't really bring up data beyond the total number of acetaminophen-related cases of liver toxicity, is that the author believes he should be able to buy the drugs separately, and is denied this opportunity by the government. After that, he says everything he can to support his beliefs, and pooh-poohs arguments against it.
Oxycodone is a very good opioid and, if you aren't abusing it, it is affordable for most people, even if you don't have insurance (http://www.rxassist.org/Search/Prog_Details.cfm?program_Id=1...). But if you need it every day to support your habit, it's too expensive, so vicodin and its friends are the drugs of choice.
