It's not bullshit, and there's nothing normal about NPD. It's a disorder, that's the very definition of abnormal.
Yes, you have a responsibility to improve yourself, and yes, you can improve. For yourself and others. If you don't, you will continue the abusive cycle you don't seem to be sorry about at all, and you seem to think it's a coping mechanism. It's not. Look up coping mechanisms, there's no mention of any of the abusive behaviors a NPD uses as "coping mechanism" as you say "in response to having a narcissist caregiver/parent".
The issue is this: a narcissist's abusive cycle only deepens the underlying cause of their disorder. And the sooner they get help, the sooner they're able to break the cycle and stop hurting people.
If you truly want to be better, get help as you say you are, but don't minimize the effect this disorder is having on other people. That's why you get comments like "quit your shitposting", people are hurt by this disorder they don't even have, and the experiences they've been through are valid. Imagine suffering from something you don't have? Like a pain in your chest because someone else has pneumonia? How fucked up would that be?
They broke the cycle from their end, but the person who did that damage is not aware of their cycle and that's scary. A lot more people need to be aware of this damage, and sugarcoating the message will not be of help to anyone wanting to break this cycle of abuse.