I believe what they are referring to is that it's not any individuals responsibility to ensure that any other individuals knowledge of their marginalization is complete. That's not saying that individuals can't do it, nor that they shouldn't call attention to specific issues as effect them at that time. It's saying that they are not responsible to do the work of teaching someone that which they should learn themselves once the issue has been raised. To do otherwise often feels like the person has to justify their existence and struggles to anyone who asks. That's an unreasonable load for the marginalized person to carry.
So not blame, just where the burthen of learning falls once an issue comes up.
https://en.wikipedia.org/wiki/Moose_cavalry