Well, how people talk to other people is a reflection of themselves. That being understandably true, I can see where the self-loathing comment came from and I would likely agree with it, even though I'm only basing that off of a few poorly had (easy) opinions over the span of a short period of time.

However, self-loathing is not innately 'incompatible' with narcissism. In fact, I would say the two can be and are tied very closely together in many cases.

Narcissism is more of a defense mechanism than anything else. It's a wall that you've built to separate yourself from reality, because reality can be harsh and difficult. In this case, narcissists build this wall in order to build themselves up beyond their own standings, which is an attempt to gain admiration and respect from either themselves or others because they cannot obtain admiration or respect on their own due to lack of abilities.

Narcissists are basically just abnormally weak people. Everyone goes through these battles with themselves, but most people deal with it in a way that allows themselves to surpass it, to defeat it, to rise above it. This is basically what is a major part of the 'learning process', being that we learn more or just as much from our failures as we do from our successes. But if someone doesn't ever acknowledge their failure as a person and instead traps themselves in a false illusionary world of their own creation, can they ever become a better person?

Keep building that wall, surely you'll eventually surpass extreme average-ness by limiting yourself so severely by disallowing yourself to learn and grow.

Hmm, is it actually a wall if nobody else can see or interact with it?