I think that's just a symptom of the user base growing smaller. Decades ago articles had far more comments. There were always troll posts but there was a lot more discussion to make those seem more inconsequential. Even if posters disagreed politically (I'm sure 2000 election threads are just as bad as any of the recent ones) there was a shared for in Microsoft that everyone could unite behind. Since then open source has won in a lot of ways. It generally rules servers and mobile phones. Even if the Year of the Linux Desktop never really arrived, every year makes it less and less relevant. Without that, the user base will find something else to squabble over.
There's also the vicious cycle that's created where this sort of behavior drives away others and leaves a larger proportion of users that engage in that behavior. It's not so much different from a neighborhood that doesn't solve its crime problems or other issues facing it. The good people slowly leave for greener pastures, but the problem causers stick around or grow worse. If it goes on for long enough you get the dilapidated ghetto or gutted trailer park that no one wants to come to and who the bitter denizens are often resentful to have visit. It's somewhat worse with internet communities because one person can use bots or sock puppet accounts to have an oversized impact.
There's also a tendency for any internet community to become a hive mind. Slashdot, for example, was never going to become a forum where Microsoft was well regarded. Anyone who really liked Microsoft quit posting here shortly after joining to find something else other community that was more open. Any community that slants towards anything will tend to continue heading in that direction as it slowly drives away whatever outgroup is has identified. This can happen along political lines as well, with Reddit and Something Awful before it being examples of this. Slashdot seems more immune to this to some degree. It's not really designed to be as much of a social media site as most other internet communities and was built at a time when no one cared about trying to generate engagement so much as fostering discussion. I don't think that prevents the problem, but it does slow it down considerably.
The user base here is likely much, much older than the average internet community. I don't think previous generations were any better than the current or upcoming generations, but they are all different in their own ways. A lot of us grew up before the smartphones, the internet, or perhaps even ubiquitous personal computing. I think that does have some impact on how we engage with others socially. However it also means that we're a lot closer to the grave than other communities. I've often wondered about some posters who have disappeared over the years. Even people I might normally have disagreed with vehemently on some topics often had insightful or interesting things to say about other topics. Over the years many have dropped off and while it's always possible that they got fed up and got the hell out of town as it were, I think the more simple explanation is that they got old and died. The internet hasn't been around long enough yet for most communities to go through this process where the people who started it all pass away. Slashdot is old enough where that's starting to happen. Anyone who was in their mid-20s when the site was started will be approaching 60 by the end of the decade. A lot of the early users were older than that.
TLDR: Slashdot is dying. Netcraft confirms it!
