^ 
I’m curious.
Are those users hesitant about flagging posts that don’t fit?
Do they, maybe, imagine that flagging will not lead to an agreeable outcome?
Are those users accustomed to the immediacy of publicly showing their distaste for something? (That’s not a loaded question. If that’s their habit, that’s just the way it is, no good pretending otherwise.)
Do they get a group feelgood factor from collective distaste?
The appearance of thick skin can be deceiving 
but I guess that if a person will knowingly speak or write in an area where negativity is a feature, the person should be prepared to apply his or her own bandage after being cut.
Or (@mcbuzz) do your people club together to feel good after one person gets cut by a slash of negadisliky?