Imagine if every thread Aureliafags kept saying "Aurelia is canon because she thanked Ash on the boat!" or Pokeshippers kept saying "Ash and Misty love each other, 4Kids said so!", their reputations would be down the toilet. Serenafags do something similar, which is why /padt/ turned against her and them.
You know what's strange? Serenafags here almost never actually talk about Serena herself. All they bring up is Amour. They almost never talk about Tripokalons, her interactions with her mother or other characters, other aspects of her personality, her Pokemon, and so on. In the few times that non-Amour related Serena discussion does happen here, it's usually by non-Serenafags. I really have no idea how it turned out this way, and surely not all Serenafags have the same attitude, but it seems that a few bad apples insist on what they want to do.