Speaking out against transgender ideology - which is much more dangerous - takes guts, which Goldacre clearly lacks.
Ben Goldacre has guts and moral courage by the JCB load. Back before AllTrials when he was trying to push this through, he gave speeches/talks to aggressively hostile audiences, unsupported, and at his own expense.
He's been a practising clinician in some very rough areas so, like many HCPs, has a courage under provocation/animosity that many people don't.
He wasn't public about it but I gather that he didn't go unthreatened for some of the work he's done in the past.
His intervention in the times of #NoDebate would have been to no avail. If he chooses to give attention to this in a future when debate is more acceptable then that would be his choice. He's not an MP, he has no obligation to one side or another. Given that so many of his colleagues and former/current associates are TWAW and have even sided with Mermaids in some spats, I'm taking it as a current public good that he's not displayed partiality in the fray.