Yes, all of what you said. It's absolutely changed as it became popular - I'd guess most of the new users over the past 1-2 years have heard about it via reddit and thus you get that same commenting style/quality here:
- lots of puns in replies
- people being very snarky
- people who downvote b/c they disagree
- people who reply just to point out mistakes
- lots of "+1 here too" replies
- a mean tone in many replies
- people who upvote off-topic stories
- people who submit/upvote White House petitions
- increase in psuedonyms like "throwaway235" or "anonymous354"
I think most of the old timers prefer the old days because we don't enjoy the above. In 2009, for example, HN was HN and reddit was reddit and you went to each for different reasons. Today nearly every non-Ask HN post on HN is either on reddit soon after or on reddit first. I'm not saying that the above didn't exist on the "old" HN - it did - but it was much less common.
That being said, I'm one of those who believes that not showing comment scores causes some of this behavior. Not my site so I don't get a "vote" per se but I do not agree that hiding comment scores has made things better.