Once an alias gets old enough, I think it counts as "standing behind your comments personally" - if you cared to go looking, you could find some pretty dumb stuff I posted years ago on other sites when I was in high school, but I'm still using the same alias.

Why use an alias? Partly the romance - online handles just feel like they come from some earlier golden age of the Internet, when it was the domain of scrappy hackers rather than big advertising corporations (it's likely mythical, but it's before my time in any case). Also, my username is quicker to type and more unique than my real name - in some ways it is a better identifier for me than my name.

> if you cannot stand behind your comments personally, why even make them

Experimentation?

> Not only that but I also never delete a comment

I delete regularly, particularly if on re-reading the comment I realize I'm a total idiot, or being unnecessarily rude or whatever. I guess if you're unwilling to experiment with new opinions you might never need to delete them..

On the contrary, I make my share of idiotic or ride comments. However, I feel that those comments, too, are part of my presence on HN, if some one cares to look (I don't think anybody does but I routinely go back and reread my lowest and highest rated comments.