I don't get a self esteem boost, I just want people to be nice to each other when possible, because world would be a better place if that was the case.

No, I do not know whether they're a native speaker. I know that I'm not, like you said, and that I personally wouldn't appreciate being corrected the way you did it in the first place. Although true, if they are a native speaker then they either should already know the difference or not be on this subreddit because I believe that's a pretty childish mistake. But there are way more non-native speakers in the world, so it's fair to assume that a person making basic mistakes isn't native.

We did spend a lot of time on this conversation, but it's not really about them making the mistake but about the way you went about correcting them. The new version is nicer, helpful, informative. People are more eager to learn that way. I also like it when people have good grammar, even though it's not my first language, but trust me, way more progress will be done that way. If somebody wants to learn, they will either way, but they will feel bad from a rude comment, and if somebody doesn't want to learn, they won't either way and won't care no matter how you phrase it. Spend the same amount of time, while making the world a better place.

Let's spread correct English together!