Good point, although I feel that real names would make things better on Hacker News by giving (1) accountability for comments (2) credentials and justification for opinions. By the latter, I mean that it constantly seems that (for example) on many posts lately involving mathematics there's an argument where one side is forcefully saying one thing that's false and covered in any good college pure math course. For third-parties it isn't obvious that one side is correct and that one side may be a professor or PhD.
I like to think my HN comments are more likely to be believed by others and useful to them because of my cogent observations or clear writing style, than because of my name which is probably not known to most people, or my degrees which are not relevant to most topics.
Most topics yes, but is it hard to accept that education and degrees are useful when talking about math or physics or whatnot? If both sides are well written I'd like to know if one side is an expert in the area and if the other side just has cursory knowledge of the area from blog posts and Wikipedia.
My personal opinion is that deferral to authority can be a useful thing. If one is a Putnam fellow, ACM gold medallist, pure math PhD, and head of research at a hedge fund, with experience at Google etc, then occasionally some post comes up in ones area of expertise and there is some blatant misinformation, but it's not worth it to reply since the people with more time to write posts and reply in the thread will control the conversation.
Hacker News has some truly great people coming in all the time, and I want to listen to them. If a world expert stops by he/she may have only time for one sentence, but that sentence is highly valuable (see: reactions to pg, spolsky, etc)
You are right that posts should stand on their own merits, but it would be nice to be able to keep track of some kind of reputation.
Are you arguing that we should share our degrees, grades, upload a CV with a picture (maybe I'm more believable when we're talking about white middle-class people if I prove that I'm white a middle-class guy)? A driving license showing that I'm allowed to drive trucks of all sizes, for the off-chance that I'm making comments on stories relating to that?
Your idea starts out simple and innocent, unless you think it through. You are not entitled to know these things. If people argue about math and you cannot judge who's right: Bad luck. That's not a reason for them to prove anything to you. If you actually care about math topics and notice that usually X is supported by most people or - after investing some time of your own - is right according to your own investigation, X gains your trust. Y, always arguing against X, is probably talking bull..
It's the same in real life. If you meet a guy in a bar and you start talking about something other than weather and nonsense, how do you judge him? Unless you're way out of line you probably need to learn if he's talking sense or regularly pulls things out of his rear end as well. Do the same here.