I dont know masses about the history of the SNP, but when I was a kid they were the 'Tartan Tories', pretty stodgy, vaguely rightwing and traditionalists.
They've reinvented themselves under Sturgeon as a super progressive liberal party who lay claim to the fountain of youth, but despite this shiny new face the largest part of their membership retains people from Salmond's era and before.
This seems to be all about inner schisms of the SNP - that vid of the FM's was appealing to one sect, the TRA subject is just a flag waved at certain sectors of the party.
I mean, NS doesn't really give much of a fuck about nonbinary rights, let's not kid ourselves. NS wants independence, wants to look progressive, wants to polish the appearance of Scotland as a young nation. It's signalling, that's all.
I daresay some of the people leaving are just seeing through how the trans/GRA issue is being used as a political trophy. There's not actually any conviction behind it for most career politicians.
Looking at it like this, I actually empathise with one of the TRAs ranting on Twitter last night - who can see quite clearly how this issue is being used.