The problem is that pretty much everyone is in some way influenced by them just by seeing them.
Do you really approach a comment at -10 points with the same open mind as one with +30?
The problem is you don’t know the moral character or intelligence level of the people who first stumbled on to a comment. If two ignorant people happen to see a quality comment first and both vote it down that comment is essentially lost to the group. I think we can all agree there are at least a few fools running around here so the idea isn’t farfetched.
So the question is do you want to trust what might be insightful comments to the randomness of timing?
If the comment was really sparkling, it seems unlikely that the first two ignoramuses would drown out the larger cast of HN. It's not all about timing.
Also, 10 people on a site that gets in the area of 200,000 uniques isn't that significant.
upmods - downmods = score