Kids who haven't developed taste yet can still just flood their case with rainbows. Easier now than ever, really. That's not who this motherboard is for, though, and it isn't what enthusiasts consider cool anymore -- it's just as gaudy to them as it is to you.
This part is going to be integrated into a really meticulously designed case with every part working together to create a theme that goes beyond just color. It'll perfect out of sight cabling, custom run water cooling, probably some action figures hanging around in or around the case.
They want performance, but also want it to look good. There's no reason you can't have both today.
(said as someone with my own PCs configured more like how you prefer... functional, performant, not loud or bright)