We do take what we dish all the time, what we pretty much never dish is public and directed attacks on individuals (or other social attacks of which there are many, such as spreading rumors). If I'm in a room with someone that is continually spouting off about all men being sexist pigs and making period jokes I really don't care, that is their prerogative and I have no right to stop them much less publicly attack them (nor do I feel the need, but that is another issue altogether).

Because they're on the inside and you're on the outside.

Is she? Why?

An insider can make any comments they like about an outsider (up to the point where the comments themselves become problematic to other insiders), but an outsider cannot say anything negative about the group or any of its members without being perceived as attacking the group and all of its members.

Basic in-group/out-group dynamics.

No, that I get and understand. I meant, why is she in the out-group? Or, more precisely, how do you know she is in the out-group?

The one is a personal insult that can be brushed off. The other is an accusation of unfairness in the entire system.

Are you surprised that the system (and the people within it) reacts to broad-based accusations about its structure, rather differently from how it reacts to angry beefs between individuals?

On a structural perpetuation-of-the-organism level, no: you make a good point. On a personal level, I do find it weird that people take critiques of a system more personally than personal insults. We were all born into a system that we didn't create; we reshape it through the actions in our lives.