That is a cop-out and not true for all comment sections.
> There's no evidence for this, and it's unrelated to the topic.
That's a huge cop-out statement to shutdown conversation, and this is about as on-topic as possible. Who are you to decide what is on-topic?
> Too often they devolve into racist, misogynistic maelstroms where the loudest, most offensive, and stupidest opinions get pushed to the top and the more reasoned responses drowned out in the noise... we had to ban countless commenters over the years for threatening our writers and subjects, doxxing private citizens, and engaging in hate speech against pretty much every group imaginable.
> We don't have the time or desire to continue monitoring that crap moving forward.
2. use the comments from #1 to argue that anonymous comment sections should be shut down
3. profit!
It's the same tactic news sources use in other contexts, too. You want to create a narrative against candidate or political party X. So find a really loathsome person who supports X and run a story about them. Perfect. Never mind that most people affiliated with X woud never associate with that person.
What it lacks in veracity it makes up for in truthiness.
Insofar as "control the message" means "we are tired of anonymous people in our comments section doxxing our authors and other people, and vile, racist attacks on our authors and groups of people", then yes, this is an attempt to "control the message."
> Since NPR clearly had a pro-Hillary agenda, the comments section had to go.
There's no evidence for this, and it's unrelated to the topic.