I don't understand the connection between this and abusers. The advice is to avoid attaching your identity to any particular ideology. What does that have to do with enabling abusers?
Things seem totally benign until something goes wrong. Then all of this “advice” starts to look totally different as you watch everyone who should act and take a stand decide they need to “keep their identity small.”
If I saw my supervisor taking home a young female employee, I'd go right to HR about it, done, next question.
This step is optional. The argument is that it is in your interest to do the former without the latter.
I think maybe you are viewing this from the perspective of your identity being how other people perceive you, rather than how you perceive yourself?
Like if you pull a drowning child out of a river, do you now become "guy who pulls drowning children out of rivers" and you have to quit your job and patrol the rivers looking for drowning children, because this is your whole identity now?
Since this is usually openly against the rules in nearly any company, of doesn't even take identifying with anything, it just takes following instructions.
Also, while you keep your identity small, reducing it to zero might not be the wisest approach.