Why does anyone adopt any sort of ridiculous subculture style? Because it gives them a sense of shared cultural identity.
There’s a bit of circular reasoning here. Do you like being loud? Going to clubs? Getting drunk every weekend? Picking up random girls in said clubs? These guys do. So to fit in and stand out, they dress and act as loud and as flashy as possible. Everyone else in the club is dressed that way, so it becomes a vicious circle of who can out-guido who.