Because it’s not true. Narcissistic personality disorder may included self loathing but it is not a requirement.
This pattern is shown by the presence of ≥ 5 of the following:
An exaggerated, unfounded sense of their own importance and talents (grandiosity)
Preoccupation with fantasies of unlimited achievements, influence, power, intelligence, beauty, or perfect love
Belief that they are special and unique and should associate only with people of the highest caliber
A need to be unconditionally admired
A sense of entitlement
Exploitation of others to achieve their own goals
A lack of empathy
Envy of others and a belief that others envy them
Arrogance and haughtiness
Praise yes but not the feeling of superiority to others as NPD comes from self-loathing.
Not sure why you’re getting downvoted. You’re right.
Because it’s not true. Narcissistic personality disorder may included self loathing but it is not a requirement.
source
Musk only needs 5. One could easily argue he has all of them.
Happens often here.