High thrill rides and roller coasters are a sure fire way to split up any group of people. Even a group of thrill seekers can be divided depending on speed, height, inversions, spinning, etc. Everyone has different tolerances for motion. Heck, people have different tolerances for things like theme and darkness and content. I remember a family trip to USF many years ago. My siblings and I were 4, 8, 11, and 14. MIB was the only ride I remember everyone thoroughly enjoying together. But I have a few memories of being frightened or just waiting for my brothers to ride something with my dad. And so my family never returned to Universal until WWoHP. Universal needs families. And I think they're also making up for lost time with all those families, like mine, that only stayed with the mouse so they could ride most everything together. That was Walt's reason for creating Disneyland in the first place and the reason why Disney is the company that it is. Yes, Universal should have it's own identity and it does. It is still the more thrilling resort, and I don't think a thrilling family coaster/dark ride replacing DD is going to change that. You don't need a park of B&M's to have your own identity.
And being the more attractive park to college kids/20-somethings means nothing when your target audience can't afford you. Six Flags and Cedar Fair can do it because it serves locals and it's easy to get tickets for cheap. But me and my college friends visiting Universal? In this economy? lmao