I apologize for the long comment but there are many details to this. You do not need to reply if you wish not to.
Religious people who hold supernatural views will always attack scientific fact which clashes with their belief system.
Ideologues who hold dogmatic views will always attack scientific fact which clashes with their belief system.
Fear of either of these groups is not a good reason to eliminate comments. Even if some people who read can be swayed - that is the weakness of those readers.
Being afraid of polarization is not a good reason either. Enforcing a hugbox where polarizing discussion is never allowed, discussion which goes against the common circle jerk is up to those who own the site to do or not. Polarized discussion is useful as when it's actually allowed it tests the fitness of arguments. People who resort to stating how they feel about something are not making an argument. People who attack others as a way to avoid the argument may be able to shift the opinions of bystanders. Politicians do it every election cycle to smear their opponents. Ignorant people can get swayed by false or misleading information. I would like more people to build the habit of personally verifying information from multiple sources. Many people are smart, many people are ignorant. Many people accept assertions purely based on who they view is an authority.
Uncivil comments can be stressing if people allow them to be, but they can also be ignored. I think it's better to become resilient against uncivil blobs of text than to allow them to have any power over you. If the rules are clear in disallowing personal attacks, and people break the rules, then their comments can be deleted. But even allowing uncivil comments to stay permanently does not mean productive discourse cannot happen.
That article is for a science based site that wishes to disseminate factual information. They wish to control public opinion, and in turn public policy by removing the threat of comments in swaying their readers against what they present as scientific fact.
They argue that spam is a reason to disable comments. Technology can solve spam.
They argue that trolls are a reason to disable comments. There are trolls who post to get a rise out of people, and should be ignored - people who give attention to these kinds of trolls are just as bad. There are jokers who want to post dank memes but are otherwise benign. But also there are people who claim that people are trolling them when really they have a difference of opinion, and so they use this as a tactic to dismiss others. "stay away from the lunatics on the net in the same way you shouldn't wrestle with a pig. You both get dirty but the pig likes it." could easily be seen in this way - how do you know people are lunatics? Some people are dead set in what they believe, and arguing with them may not shift their view, but just as with public debate the real value in public comments isn't the dialog you have with the other person but that others can view your public dialog and make up their own minds.
They argue moderating comments is a time burden. This is understandable. Paying people to moderate can be costly. Letting people moderate for free can open the door for power hungry individuals to block out views they disagree with personally.
If a site wishes to disable immediate public discourse that is their choice, but it removes any sort of value that could possibly come from comments, and does make them look cowardly if it's apparent they did it for really the wrong reasons. Throwing the baby out with the bathwater, hiding from difficult discussion, attempting to enforce a narrative with no dissent allowed. Disabling comments will not stop the discourse from taking place elsewhere, and I think the places such as fairly moderated reddits which allow more open discussion will ultimately be seen as more valuable, and not only that but are the hubs where culture at large has its views and tastes made in ways with much more dramatic potential.
I would rather people learn to be skeptical and develop their critical thinking skills than to treat everyone like children because some people have weakly developed minds, are lazy, easily influenced. Ideology and religion both poison minds, but both also eventually die to the facts. The internet is where they go to die. Even if in the short term people believe they are making the world a better place by not allowing any discussion at all - the discussions and arguments are still happening elsewhere and ideas are constantly being pressured for fitness.
tl;dr I think that the site you linked removed comments largely to wash their hands of having any part of the discourse. Them removing comments will not eliminate the persistence of people who deny science. Fake articles and personal attacks will still go on, but they will go on elsewhere, and by removing comments they disable the ability for reasonable, thoughtful people to possibly gain additional insight into subjects from other science enthusiasts who may know something the article writer doesn't.
/r/AskHistorians does a better kind of thing with strong requirements for posting information. You must cite your claims as best you can so that they can be verified as being factual among other needs to meet posting quality.
with better moderation to keep away the worst
I'm against heavy handed moderation too, because what you may think are the worst kind of people is your opinion. If the moderators are moderating fairly and with transparency this is can be less problematic, but I've seen it abused too. I've been called the worst kind of person by radicals for disagreeing with them. I've been blocked by major sites because I am not hardline enough for them. Those sites have comment sections that are very heavily moderated with anyone who disagrees deleted and banned.
Comment sections will always be chaotic if there is no authoritarian moderator making sure to clean for ideological purity. Sometimes these kinds of places can be the best, because they allow people to speak and others to judge their arguments without a moderator stepping in and saying their opinions are just too problematic to even be allowed.