I can see you point and I thought it unwise.
However I think the point the poster was making was not "trans people are abusers" but " this is an example of who might get in to the female estate if Self ID is passed".
These discussions are uncomfortable and absolutely need to be carried out in a way that does not demonise groups of people. To me the gender identity and trans status of the perpetrator does not matter EXCEPT for the fact that laws some are pushing or see as no issue might allow a male sex abuser to end up in the female estate. That is what matters, not how the offender dresses, presents or identifies
This is why "no debate" is not helpful as it prevents those issues being identifed and separated.
But I agree putting it in to the current febrile atmosphere of the Other Place was not a good idea.