Yes, I certainly am aware of the technological solutions to this problem. Nevertheless, I am still baffled by the apparent stigma towards linking to your site in the URL field, which seems like the natural, obvious, and right thing to do.

I would welcome an explanation!

Here's my (noobish) understanding: On Hacker News when you submit you have the option to include a clickable URL -or- text. The preferred thing to do is to include some text rather than the URL.