You know, as an instructor, I don't mind anyone in my class doing their own ride (as long as they don't disrupt the class with no-handed cycling, popcorn jumps, or anything else that is totally contradictive), but I will tell any member that attends my class with their own music and earbuds that they need to leave. Why? Because I teach a "group fitness" class, and as such, I do expect the participants to listen to my safety cues, and at least the class profile...otherwise, it turns into a room full of individuals that are doing their own thing, and while that's not a bad thing in an aerobics area, it doesn't really fly in a class situation. This is why facilities have "group fitness classes" and also have an aerobics area.
My .02 only.
Vertically challenged, but expanding my horizons.