I am not seeing what the issue is here, with anything Anthony, JoeyLittle, others said.
Stating a current research and clinical practice point of view on diagnoses or theories on the formation of personality does not a personal dismissal make. Nor is it bulldozering anyone into the ground. They have not attacked any single member here, nor were hostile, nor have tried to deny people and their lived experiences.
And, frankly, if you are D.I.D., then what a joe on the internet says about it will not change the fact. Nor will in person encounters, or trying to persuade you otherwise. What that can do is what would happen with any singlet people, added hurt, trauma, confusion, denial, anxiety, what have you... but will not change your lived exprience. So it is basically dismissable. Not a threat. Not a threat to a core being, either.