I would dispute this claim.Torture doesn't work in real life.
The US army field manuals and instructions issued to captured prisoners suggest that prisoners should expect that in the long run torture always works, and that they should not expect to hold out against prolonged torture by strength of will. There is abundant evidence of torture 'working', especially against prisoners who have not been trained in techniques of deception.
I will in fact also dispute the claim that torture is a common practice in D&D, because generally there is no mechanism in D&D for using torture to compel anyone - PC or NPC - to cooperate. I've rarely seen PC's attempt torture, and those that do pretty much abandon it quickly when they realize that the rules give no practical benefit to torture. And likewise, NPC's torturing PC's is pointless, since by the rules the PC's never have to 'break' and I've never really felt a need to make up rules about torture since I don't really want it to be a focus of play.
I think that ultimately there is a proxy argument going on here. I think the real point of the argument is, "Torture shouldn't be a focus of play." And that is a much less controversial statement that doesn't need any sort of claims about the effectiveness of torture in reality or in play.