It's like removing karma on articles, and saying 'if you don't have time to read the articles and evaluate for yourself which ones are good or bad why are you even here'?
For me there are a number of answers to your question:
- I love HN because I get to learn about lots of stuff I know very little about. For example I'm a business guy not a progammer, but I love to learn more about the non-business things. I genuinely can't judge the 'good or bad' on my own on some of this stuff. The karma gives me a quick and simple way of the community - this wonderful, intelligent community - pointing me in the right direction.
- It also shows where my comments might be off base - not because my comments karma is high or low (which I still see) but because I can see if the counter arguments are rated highly. For example I can't see if your comment is highly regarded or not. If was +40, compared to +1, I'd be more likely to think 'hmm, maybe I'm wrong on this after all'. Sometime is not just the power of the argument that changes minds, it's the weight behind it. I can't see that weight now.
-sometimes I quickly browse HN with some minutes of down time. Sometimes I read in depth. I now feel I'm being forced all the time to read in depth. Whilst that sounds good, in practise for me it isn't. Instead of more in depth reading I'm just cutting out the browsing, so I feel ultimately I'm getting less out of HN.