The wizarding world has an… interesting stance on their ‘heroes’. Namely, each and every single magical 'Hero' is expected to be an honest to god, Grade-A asshole.
It's not their fault… mostly. An slew of Heroes who turned out to be massive douchebags was probably what influenced this public perception.
Merlin was a womaniser. Charles Dupont was a money laundering scumbag. Richard Marigold was a sexist slave owner. Albus Dumbledore insidiously managed to bag himself three powerful positions and hence ensured a stranglehold on British magical society, you know, the works.
So when Harry Potter showed up for his first year at Hogwarts, almost everyone, from the teachers to the house elves, expected him to be an unbearable ass.
He wasn't.
Young Harry Potter was polite, kind, and friendly. A bit out of his depth, perhaps, and unsure of himself, but a nice human being nonetheless, despite all that was said against him.
And none of them understood why. Or how.
As the years passed, even the last naysayers were forced to come to terms with the truth. Harry Potter was not an asshole.
And so, his fame skyrocketed. Across the world, wizards and witches shared increasingly fantastical stories of Harry Potter, the Hero-Who-Was-Nice.
And Fleur Delacour couldn't stand it. She didn't understand how the others couldn't see. The boy was clearly biding his time, waiting for his public perception to improve, so he could start to show his true colours without fear of repercussion! So many ‘Heroes’ had done it before! It was an insidious, masterful plan worthy of a dark lord! And she would prove it! Fleur would be the one to show the world Harry Potter’s true colours!
And The Triwizard Tournament would be her best chance….