In full agreement here as well! The ones that get me are the 'my cat is half the size of a true Maine Coon but is a longhaired tabby so must definitely be part/full Maine Coon'.

Rather reminds me of people trying to identify their chicken's breed, only ever looking at the plumage coloring and never at any of the other traits. Breeds are more than just a coloration!
People are constantly asking me if my cat is a Ragdoll or Himalayan or Siamese/Balinese, or simply just referring to him as such when reacting to his pictures, but, well, he didn't wander out of the woods with any pedigree papers in paw or anything, so as far as I'm aware he's just a really pretty domestic longhair. I have some suspicions because there
is a Balinese breeder in the area and he has the traits for the breed, but until / unless I have him DNA tested or something I will always tell people he's a domestic longhair. I love him so much that I don't care if he's not some exciting purebreed.

I'd never heard of the term moggy before now!