The only issue is knowing if you should presume to "correct" another poster or not. That old saying goes, "your rights end where another person's starts". You have your right to speak your mind. Does it matter if it's a pm or on a public thread? Unless you can read everybody's mind you're not going to "gently nudge" each poster you want to correct in the correct manner since some would be upset and argue back if you corrected them in public and some would be offended if you corrected them privately since that would not allow them a forum to publicly defend in if they disagreed with your correction.
And you don't know what people want to be corrected on. Someone told me I was accidentally racist by saying I felt gypped since gyp was short for gypsy and was a romanian racial slur. Scale of 1-10 for me, only 2 or 3 level of interesting. Someone corrected me on my thinking in the nature vs nurture question when old wives tales say we only use about 10% of our brain at once then no one operates near their ceiling of capacity. But I was corrected that parts of our brain have different assignments so using more at once would be applied to the task at hand but would be painful. To me that correction was interest level 9 out of 10. Also, I was recently corrected on misinterpreting data. Someone proved 41% of a genetic factor in g, so I assumed the other 51% was nurture. Some guy pointed out that just because they found the chromosomes creating the first 41% didn't necessarily mean the rest was nurture, it could just as well be other chromosomes they haven't looked for yet. That is the kind of correction I like. I was corrected about something I was trying to think through. The first type of correction is an interesting trivia factoid. I have a bone to pick. And, sadly, I know this is offensive and here I am saying it anyway. I've seen vocal advocates of the child led learning movement being the worst ones for making the trivial corrections on other adults statements, not the constructive on topic feedback like the second two. Ironic, huh.

Youth lives by personality, age lives by calculation. -- Aristotle on a calendar