What I find interesting about this is that you're basically saying that their signal isn't costly enough to make you feel good.

It's not about the effort or cost, as if I expect people to be more honest when they are using more resources. The problem is that the same stock phrase could be said of anything, because it is vague and difficult to interpret at lower levels of abstraction where its truth value could be evaluated. Writing a sonnet in general praise of insights would not be nearly as valuable as identifying a single specfic insight and why it is useful, though it would be a costlier signal.