People can be wrong about things, and comment scores are useful information that helps us know if they are.
"that is not how mysql works" with 2 Points
And
"that is not how mysql works" with 102 points
Are not the same piece of info.
I don't see any benefit to hiding this from people. It also helps newbies understand the customs here (they can get feedback on other people's comments)
edit now that I'm not on my phone:
When you google things, you probably skip over results like daniweb, about.com, or expertsexchange.com, and hope for a stackexchange page.
The little URL at the bottom of the description tells you "hey, this is from $foo source" and you're a smart human being that can put this information to good use.
Of course, you could make a case that this is bad, because you should read each one of the results and judge it based on its merits. Maybe we should even strip all of the identifying information away from the page, and just let it stand on its own (this would be a neat experiment, actually [and that's the experiment that I think we're performing here]).
The point counts on the comments act just like the URL does on google results. It's not saying "this is definitely 100% accurate", but it is useful piece of information that we can put to good use. Depriving us of this information doesn't break the comments, but I have certainly found myself reading comments a bit less lately as a result of it (instead of actually reading comments, I'm usually just skimming them now). With comment scores, things seem to have a bit of order to them, without, it just feels like a lot of people shouting at one another.
(Maybe this was the point?)
Naturally, I'm never going to stop reading HN; it is by far my favorite website on the internet. Complaining about the lack of comment points here is like complaining that my favorite bar switched to a new, very slightly different glass. I can see the difference, but it's not really going to change my habits.