The issue with pugs is not that they’re evil or bad creatures, it’s that humans have selectively bred them for their looks, but that’s lead to the animals suffering because their breeding means they have massive problems with breathing, their knees, spine, eyes, etc. That’s unfair on the animal.
It’s like saying we want to eliminate genetic diseases like Down’s syndrome or Haemophilia. Nobody’s saying individuals with those conditions are bad, it’s that we don’t think people should be born with conditions that give them a worse life.
Now for dogs it’s a bit more complicated because those conditions are afflicted upon them by us purely for aesthetics, and if dogs are banned that inevitably leads to some being killed which isn’t very fair on those animals, but if we can’t find a way to reverse the worst aspects of their breeding is the only way we can prevent further suffering.