You have an evolved sense of online self which I would guess is not the case with many of those you interact with.
From my own perspective this is not how I or indeed many others view their "online persona". For some our online personas are simply an extension of our offline personalities, We try to communicate online exactly as we do in real life.
For some others they have an even less sophisticated online self which, due to the de-inhibiting nature of anonymity results in them becoming assholes.
i recall similar talk from kleinbl00 a while ago. it was in a thread made by a first time poster and it detailed some heavy personal life stuff. klein and others thought of it as a failure because the user starting their "hubski persona" with such a post seemed gauche. i remember finding it really interesting seeing these concepts discussed so starkly. i will try finding the thread but i do not trust my searching capabilities.