yes, this is laudable. but it's not either/or. it's both. it has the potential to be a non-obvious ground of solidarity, what weberians will call value-rationality, as opposed to goal-oriented rationality. there's no goal toward which the chatting must move, but that chatting is valuable, in and of itself. that's the same idea behind what i called "talking back". no one believed that talking back, as citizens, was really going to change a politicians opinion, though they dared keep hoping. what they realized was that it was a social practice through which they built solidarity, felt powerful as a collective group of people on the move.
what I'm thinking of is the use of "it's just my opinion" not just to protect oneself from being enmeshed in a heated debate, it's an attempt to foreclose debate entirely. it's actually a tactic used to close down the debate and the person using it is trumping their interlocutor, or so they think. by claiming it's just my opinion, it is an attempt to claim privacy for something you're not really keeping private. instead, you keep whipping it out in public and stroking like mad and then getting upset when someone dares reach out and touch it. as soon as anyone touches it, Ooop! pull it back in and don the raincoat emblazoned with, "it's just my opinion." it's the _just_ that is disingenuous.
it's used as a way of holding fast to your opinions without ever providing someone with reasons and subjecting those reasons to discussion -- or a chat :)
i think you're right that i should try to rescue a more positive meaning from the people i spoke with by revisiting my field notes, though.