People get suckered into the sunk-costs fallacy all of the time, and managers of large communities are going to be extra prone to it when they're told they'll have "their communities" taken away from them.

Remember, these people are fighting to "save Reddit". They see the possibility of having corporate friendly scabs take over as a community-destroying and a Reddit destroying proposition.

The event horizon of a black hole is the 2-dimensional surface across which the possibility of turning back is eliminated. At that point, space and time become so twisted that there is no longer an "outwards" direction. Every road leads in. But in supermassive black holes, that event horizon is so far away from the centre that the actual tidal forces -- the forces which pull things apart when they're near large gravity sources -- are remarkably weak. You would not notice the difference between being 1 km above the event horizon and 1 km beneath it. If you weren't being careful, you could cross that event horizon without ceremony and without realizing you'd doomed yourself.

This is how it is with big services, too. The thing that makes them irrelevant happens long before revenues or usage decline. In fact, there's likely still growth! But there'll be an inflection point in the acceleration that those who don't know what to look for won't even notice. Then it could take months, or even years, for things to turn around and decay into nothing of value.

These mods are trying to save something that has already experienced its killing blow. Something that will cease being what it was long before it ceases to be. Something that has already quietly -- though not too quietly -- slipped past the event horizon.