Yes, that is partly true but the SOP also has production in it and the APA is working on getting production back in the standard.
If you want to have pretty birds, or as you said "Fancy" then you can still have them be productive.
Some seem to use the term non sop to justify birds that are actually un healthy. Healthy pretty birds will be more productive and will live longer. I think it is a good thing if members of a breed look like the breed they are supposed to be. If one does not breed towards some standard for a breed they will no longer be that breed.
Because chicken breeds are not determined by genetic testing but by appearance. For example, a red bird is not an SOP Rhode Island Red just because it is red. It has to have the shape and other Characteristics too. Otherwise you will have something that looks more like a Cherry Egger. The same is true for Black Australorps. How many of them from preservation places like Sand Hill do not have the correct curve to the back. Many have a purple sheen and not green. They are also too small and thin. Not all black chickens are Australorps either.
Those may lay eggs well because that is what hatcheries live off of but they do not produce good meat.
What I am trying to say is that you can have both production and a pretty bird that is in the realm of show quality. It is up to you because, after all, they are your chickens and you can do whatever you want with them.