I don't quite think it's the word you were looking for...
I mean, is sickle-cell anemia abnormal? If you're not homozygous for the trait, it helps protect against malaria.
Playing Blockland is pretty abnormal.
Being black in America is pretty abnormal.
Liking MLP as an adult is pretty abnormal.
None of these things are immoral, they're just minorities.
The problem is that words like "abnormal" and "mental illness" are taken as insults when really they don't have to be.