The structure of Reddit’s content aggregation and curation leads to a regression to the mean. Things that are broadly agreed-upon, even if wrong, are amplified, and things that are controversial, even if correct, are attenuated. What floats to the top is whatever the hive mind agrees is least objectionable to the most people.
One solution that seems to work elsewhere is to disable downvoting. Downvoting makes it too easy to suppress controversial perspectives. Someone could put forward a thoughtful position on something, and if a few people don’t like the title and hit the downvote button, that post may be effectively buried. No rebuttal, no discourse, just “I don’t like this, make it go away.” Removing the downvote means if you don’t like something, you can either ignore it, or you can put effort into responding to it.
The “downvote to disagree” thing isn’t just an attitude problem, it’s a structural issue. No amount of asking people nicely to obey site etiquette will change the fact that the downvote button is a disagree button. If you don’t want a hive mind, you necessarily need to be able to allow for things you don’t like to be amplified.
Twitter is actually better for this than Reddit because it has the quote function. You can amplify something you don’t like as a way of getting other people to hate it with you. It’s not perfect, but there’s no way of having it both ways. “Reddiquette” was never a real thing, just a polite fiction that ignores the Eternal September world that we live in.
If you have the same structure as Reddit, you will recreate Reddit. Lemmy isn’t going to be different if all the incentives and interactive elements are the same.