It's the latter. A comment with 30 points, say, a year ago would have been very unusual, but now that's a pretty typical score for the highest-rated comment of any link in the current top 10.
Unfortunately, this seems to coincide with HN following the same trajectory as early Reddit, and that makes me sad.
While I do share your sentiment fearing that the community will change, I don't think that the karma totals are really a good gauge of content/comment quality on HN. Just because more people are here to upvote does not mean the comment is of lesser quality than before (the opposite is also true...)
A quick fix to this could be a sort of weighted comment score. Maybe the karma points / by the number of karma points added that day to give an idea of scale in comparison to the overall size of community. I'm sure others could come up with something more precise, but it's a start.
I don't like capping, sometimes there are truly exceptional comments that deserve 99.9%ile rankings. What about some form of logarithmic decay? Perhaps the first upvote should not be worth the same as the 101st.
By the same token, it seems to me that the ratio "story upvotes"/"number of comments" has gone higher and higher recently.
I'm not sure what it says about HN though. I might not necessarily be a bad thing actually. I'm not really for having a flood of comments on all the stories.
Unfortunately, this seems to coincide with HN following the same trajectory as early Reddit, and that makes me sad.