As I say, it is my opinion and impression from Stonewall recently (I’m in the UK and they pass through my sphere on a regular enough basis) that they are indeed moving towards the position that the article author suggests.
That is my impression without a hard cite to back it up and it is open to change.
I do agree in general, the problem is when you get to define “bigotry” in your own way as “that which isn’t in perfect agreement with us”. regardless of any reasonable argument that may sit behind such a position.
It is a no true Scotsman scenario.
“we won’t engage with bigots”
***“OK, lets hear your proposals”
“here are our proposals”
***“I have some reservations about your proposals”
“Only a bigot would refuse to agree with us fully”
***“But I disagree with some aspects of your proposals and I’m not a bigot”
“bigot! we will not engage with your hate speech”