Always super easy to say for someone else. Why haven't most of the people in the US government quit by now? In fact, insecurity about getting an equivalent job is a real thing. Not wanting to abandon a project you've worked on and expertise you've developed is a thing. Not wanting to abandon people you've worked with is a thing. Thinking you can do more good from within is a thing.
Even for those who consider quitting in protest, waiting until just after the next bonus/vesting day seems like a reasonable concession to other psychological or financial needs. Then that date rolls around, and all of that inertia is still there. Expecting others to make a hard decision that you've never been in a position to make yourself seems unrealistic and unhelpful.
[ETA: I don't mean to say this particular person has never been in that position. I don't know them. I've even forgotten their name. But I've seen this sentiment expressed many times and it always seems facile.]