I'm glad you're doing well Sabrina. While I do have periodic remissions, they're always quite brief for the most part. Even if I cannot fully fathom the viewpoint of a fully "normal" or at least un-afflicted person, I still have a few theories pertaining to the matter.

Listed in no particular order I would probably say:
1. Unresolved personal weakness, lack of self-esteem, self-centered, no self-actualization

2. Ignorance, stereotype tinted viewing glasses, traditional approach with everything as character flaws

3. Fear, deviation from norm too strange, impeding upon the structured world they know

4. Greed element, if there's no immediate personal gain in their lives for helping sufferers then there's no point

5. Bandwagon, fear of what others may say if they associate themselves with mentally ill, confidence of correct opinion through popular opinion on mentally ill

6. Shame, similiar to bandwagon however may be more geared towards family and friends, stronger because of personal association as well

Probably more I could think of but I think this covers a large portion of it.

Anyways, best wishes,
~Monsieur