Would you approve a (blog) comment where the commenter's name is "Best Way To Loose Weight"? Any sane blogger would never approve such comments even if it is relevant to context. Do you know why?

As comment author is linked with author URL, such comments are obviously intended to highlight the keywords he wants to increase search engine positioning and ranking. Does that sound Latin?

In simple terms, search engines like Google determine the value of a page by looking at the amount and quality of pages that links to it. It also ranks the page higher for keywords which are more frequent in links to that page. Keyword stuffing author name field is how spammers try to increase the SERP (position in search result page) for their target keywords.