The influx of Redditors has had a detrimental effect on Lemmy.
I'm a long time Lemmy lurker and occasional Redditor. Since the Reddit influx, I've watched the frequency of shitty Reddit-type behavior, e.g., combative comments, trolling, and unnecessary rudeness, just sky rocket.
I'm happy to have more content on Lemmy, but I wish the bad actors and assholes would have stayed on Reddit.
Yes, I realize the irony of posting this on a new community that's basically a Reddit transplant.
Unfortunately I think this just reflects human nature. The more people you have the more people you have at the fringes who are aggressive, or trolling or even just selfish or insensitive.
Also it's easy to come across rude when posting in text - anyone who works with colleagues via email will find the same problem of one meaning being intended but a different meanong (such as tone) being read by the recipient.
When you have a small community your names become familiar and there is something personal about the interactions. Once the you have a huge community people become anonymous and that allows bad behaviour to flourish. I barely ever saw a name twice on reddit and that's happening here too. I got to the point on reddit where I'd post a comment but I wouldn't ever read the replies as I was fed up with dealing with the negativity.
My hope for the fediverse is that there will be multiple versions of the same communities so that we can have closer knit versions of communities as alternatives to the 1m+ chaotic versions. Small communities are where you can achieve decency and kindness more consistently.
Also I assume that unfriendly behavior, and atmosphere it creates, discourage unaggressive or less typical posters from participating in conversations. So those insensitive people will end up being overpresented in the comment section.