I used to share that opinion, however I now can not help but love them.
They are not man made in the sense of us playing with the DNA physically. Instead, mutations appeared while goldfish were being kept as captive pets. And people liked these mutations, so bred them. This is exactly how all goldfish in the trade became so gold, it is not a natural colour.
So in truth, all of the goldfish are unnatural as they were originally just silver or green in colour, with short fins. Like the carp in the various wild locations today.
But I know exactly what you mean; some of these variations/mutations can be quite ugly and appear to be uncomfortable for the fish. My general view now is, as long as we dont physically play with the DNA, the fish do not get let into the wild, and are not in pain, they are okay.
I think that is a fair view, and has nothing to do with personal taste.