I don't think that's true, they just aren't usually motivated to do so: people tend to want more to win than to know the truth.
There are a few threads here with people making very strong devil's advocate arguments, but that's because we like to argue more than most people (that is, there's motivation).
As PsYcHo said, it can even change your own opinion on things (particularly if it's not that strong to begin with).
Another obvious example: Despite agreeing on veganism and the general conclusions with Isaac with regards to Name The Trait, I and other members here argued against it extensively and debunked it as a bad argument for veganism. You don't have to disagree with the conclusions to recognize something as a poor argument for something you agree with. Vegans can and do debunk other vegans' bad arguments.
We just had to be motivated to look at it critically (motivation that Isaac provided us in spades by being Isaac and refusing to consider friendly criticism).
I don't agree with absolutist arguments like Haidt's; there are plenty of people who care about efficacy more than dogmatic adherence to tribal arguments. Also, as arguments are better formalized the easier it becomes to recognize problems. We have a well established tool set to do so in formal logic. It's trickier with empirical arguments, but there we have professional consensus to lean on so it shouldn't even be necessary to discuss.
If you're presenting an argument you know will not be a challenge ant that you know the answer to, that's not playing Devil's advocate, it's coaching. It's about as bad as presenting an argument you know has an obvious counter-argument you can't answer. It's something that might happen on occasion, but is best avoided.
Or encouraging ideological diversity inside the group, and discouraging prohibition of criticism.
Did we watch the same call? Dillahunty cleaned the floor with Richard. He's obviously thought about these things quite a bit, and engaged in many private discussions on the matter.carnap wrote: ↑Sun Mar 25, 2018 1:52 pmAnother tactic that seems common is that arguing with outsiders that clearly aren't well versed in underlying topics. A recent example of that I've seen is when vegans started to go after Matt Dillahunty on a show that had nothing to do with animal ethics. Its very clear that he hasn't thought about the topics much so arguing with him does nothing other than giving you a sort of cheap sense of victory.
Dillahunty is mostly wrong, but Richard's arguments completely missed the plot.
There's a thread on it here: http://philosophicalvegan.com/viewtopic.php?f=7&t=3800