The banners absolutely had a major impact when they were first flown for golden. That **** goes all over social media, and even into the mainstream media.
The administration doesnt want negative banners flown over their events. It's the same as when controversial billboards are put up. People dont want to be publicly targeted.
Theres nothing childish about it. It shows that fans are paying attention and that something is clearly wrong.
That being said, I would never donate to a banner to some highschool kid. That would be a massive waste.