The point is just to react level-headedly by trying to understand the other person's perspective and reason for saying what they're saying.
It's a huge mistake to frame criticisms of tulpamancy from within the tulpa community's mindset. Where we may be assuming tulpas are legitimate people, and we're interacting with tulpas in the community daily - someone else simply hears "I hear a person in my head that I think is real and not me", which is perfectly fair to set off alarms when they have none of the same context as you.
So just, be level-headed and consider their perspective (so you can know how to deal with the conversation better)(edited)
I... don't think I can add anything else to the original conversation at this point
Misreading (if that's what happened, An never said she did) happens, all good
That comparison is assuming the person has good technical knowledge of tulpamancy, but someone just hearing about tulpamancy and saying it's bad is more like "You're painting your house? But paint has asbestos and can make you sick"