I agree - it is a group thing and is why I like spin classes - there can be (and is with my friends) a certain competitiveness involved.

If I do my own thing its usually instead of doing the popcorns and jumps, I sit and spin. I never use my iPod during class, except for one time... unfortunate combination forced me to. The instructor's music really suck, was incredibly loud and a group nearby were talking over the loud music. I needed to go to my own "happy place". I did however continue to do what the class was doing.