I think the problem with the trans issue is that it has no firm foundation in fact, so there has to be something other than a cool, reasoned, presentation of verifiable evidence to defend their position.
Hence the 'no debate' - well, of course no debate if you don't have anything solid to say on your side of the debate.
Other strategies are to constantly change the terms under discussion, without ever clearly defining them - the recent appearance of 'trans+' is an example.
And of course to go on the offensive, to aggressively oppose anyone who disagrees with you, to avoid engaging rationally with them, point by point.
There are so many examples of that on this board: a trans supporter comes on and makes statements which are demonstrably untrue - not matters of opinion, but of fact. Somebody quotes some statistics or a verifiable source pointing out the opposite - no name-calling, no hatred, just - look, that's wrong, here are the facts, and here are the sources so you can check it out for yourself.
How many times have we seen the discussion turn into attacks about being hate-fuelled, bigoted, transphobic, ignorant, old, an echo-chamber, 'I've seen enough, I'll leave you to your bigotry' and they're off.
There's a factual void at the centre of transgenderism that makes it fragile, so when pushed to explain itself rationally, the result is often aggression, and where possible silencing - or drowning out with noise, in some cases.
I don't know if this is the only issue where people are cancelled, but it's a very neat example the use of DARVO - Deny, Attack, Reverse Victim and Offender - in the public domain.
I often think that sociologists of the future will have a fascinating time working out how, in the 21st century, a tiny group of people, with very little evidence or logic on their side, managed to wield such disproportionate influence in so many areas of some societies.