Here is a bit of background, before I respond to this.
A Jewish divorce is the reverse of a Jewish marriage. In a Jewish marriage, the husband acquires his wife and in a Jewish divorce he releases her. If he refuses to release her, she is an agunah- a chained woman.
The laws surrounding Jewish divorce are clear. They state that someone who refuses to release his wife is an abuser and should be shunned by his community and even beaten until he agrees to release her. Unfortunately, as a community, we have abdicated this responsibility.
As a result of our collective failure to make gett (Jewish divorce) refusal an absolutely abhorrent and socially disqualifying behavior, there are many agunos today.
This is not really a failure of halacha, it is our own socially created issue.
As such, many advocates have called for halachic solutions so that women can be freed despite this reality. One such solution is stated as an option in halacha and it is called bittul kiddushin. Essentially you nullify the initial acquisition, making the release unnecessary.
However, again because of our socially constructed conditions, this approach has recieved a lot of pushback, to the point that it is extremely rare for a beis din (Jewish court which grants the divorce) to agree to do it.
Therefore agunah advocacy really involves not only actually finding a way for any specific husband to give his wife a gett but also actively changing the narrative around acceptable responses to a gett refuser.
This is why even if you acheive the former (get someone their gett) if your actions further enable gett refusers, you are a bad advocate