In my experience, if a video has comments disabled, it's probably bad. The lack of signal is itself a signal.
https://www.youtube.com/watch?v=d9dO_XBt0k8
I believe it is because they see themselves as 'above' YouTube. They don't take the risk of having a Emacs/Vim flame war in the comments and detracting from the points in the video. By disabling comments, the conversation is kept civil, because it isn't there.
They are not resourceful enough to curate a forum, so they prefer no forum at all.
Most organizations (education, government, for-profit, NPO, you name it) that use Twitter rarely if ever interact with any other Twitter account except for preplanned promotional stuff. If you noticed, Twitter added the ability to limit replies. That was solely to please the corporate world who don't like it when someone jumps on the stage that is their platform.
McDonalds doesn't like it when they tweet about their "green initiative" and PETA replies to the tweet with something about beef using x amount of land and y water compared to other food sources, or just a GIF of a cow getting slaughtered. BMW doesn't like it if they tweet about how much they spend on training techs for "world class service" but someone replies with a picture of an engine with a hole in the block because a dealer tech forgot to tighten the oil plug properly after an oil change. Limiting tweet replies means that tweeting for corporations is now a "safe space."
There's an entire business segment dedicated to providing tools to social media teams to alert them if someone who actually is "important" interacts with their social media account. Patrick Stewart tweets about his Juicero blows a fuse? He gets a replacement hand-delivered by a young marketing intern in a star trek uniform who gushes about how she grew up being a fan of "Bev."
You tweet about your juicero blowing a fuse? Nobody at Juicero even sees the tweet, because their social media monitoring tool looked at your profile, saw you rarely get more than 30 views and 2-3 engagements, and knew you represented zero threat to the brand.
If by they you mean Google then I agree. Google reaps the benefits, to the tune of billions, while deflecting as much accountability as possible. Google's entire m.o. is to build enormous scale through software automation without providing any human-level support to its users. Large changes (like the removal of dislike counts) are made only under pressure from powerful groups, unless Google deems such changes to be profitable.
Otoh creators can delete comments. So the comments existing and being positive about a video is not a good signal for the video being good either.
For example, a Yelp rating itself is useless until you also combine other signals such as the number of reviews, the type of restaurant, and the popularity of Yelp use in an area, and then I find Yelp ratings potentially very useful. Same with Amazon reviews, Rotten Tomatoes scores, or any scoring or review system.
Some other reasons:
I find it irresponsible on Youtube's part, to maintain a commenting platform with such a tremendous budget, and yet without meaningful discussion moderation tools that could be found on much lower-end platforms. These tools are a minimum bar for basically not promoting abusive behavior.
Also, disabling comments helps me to communicate that they are not a channel I monitor for feedback or questions. I just don't have the time to monitor them, and in Youtube's case this means I either have a potential commenting cesspool on my hands or no comments at all.
To some people this is a huge red flag maybe, but I would wonder if they really understand what it's like to be a publisher on the platform. Again and again I have seen good channels derailed by the absolutely broken commenter-publisher feedback loop...
It is not in the interests of almost any site or platform operator to limit drama, trolling, etc. They want the page views, the time spent in-app/on site, the emotional energy and investment.
Look at celebrities. The job of their publicists is to negotiate with other publicists to manufacture some inconsequential tiff that puts the names of their clients in the media.
You picked no discussion. So now nobody learns anything new from eachother and you turned YouTube into a TV channel with one way communication.
But you drop "censorship" front and center about some random dude's YouTube channel and you're doing some sterling fearmongering throughout the thread in general so I'm going to be honest, I gotta think this is less about any sort of freedom to speech and rather about the privilege of being granted time on somebody else's soapbox--the demand to listened to.
Get your own.
The amount of trolling (or just outright stupidity, hard to tell sometimes) on e.g. CS conference videos or lectures by women is insane. I entirely understand that the organizations putting those videos up don't want to deal with that nonsense.
Official Rammstein videos have comments disabled but for a different reason.
https://www.youtube.com/watch?v=NeQM1c-XCDc would attract ugly comments from all extremes
Negative feedback is not always given in good faith.