People love to throw this sentiment around literally every time any kind of platform does something shitty, and it's certainly very effective at demotivating people from even trying to do anything about it. It would be great if people stopped claiming this, because it's really not helping anybody and makes the job of resolving governance issues so much harder.
This specific case is actually a good example of how the sentiment is completely wrong, too; with the right strategy (which was what happened here) it's clearly possible to get people to move en masse. As evidenced by Freenode bleeding users to Libera at breakneck pace, and effectively all projects having moved over.
Bottom line: you might not want to put in the effort to solve governance issues like this, and that's fine. But please stop actively telling other people that they won't succeed.