As Willow said, smaller things are often talked about, both under flock and in public. But they're smaller, they don't always get a lot of notice. Often they don't ever go beyond one person's flist. If you're talking about discussing smaller fails on your journal, chances are they won't get that much notice, either. (And unless the author is on your flist or you or someone else points it out to them, chances are they will never know.)

I absolutely think you should discuss *isms in fic if you see them and have the energy to do so. And honestly, it doesn't have to be a huge discussion. Just by noting it, you are making people aware of it when they might not have before.