Is a concern for what other people think the only relevant factor? How about respect for other people? The way people behave tells a lot about what sort of people they are, which has some weight with whether or not I want to discuss anything with them. Someone who owns up to their mistakes is far more likely to be taken seriously -- at least by this observer -- than someone who shrugs off responsibility.

Posting as an anonymous guest is one way of shrugging off responsibility for one's words. It's like saying "You're not important enough, or this conversation is not important enough, for me to register a stable name." If it's not important to you, why should I care to discuss it with you?

Alex