You're theory's probably about right, as I'm in the same age bracket as your co-workers. Having said that, I do know plenty of people my age and younger who are as obsessed by SW as anyone.
As someone who hadn't seen any of the other SW films before watching this one, obviously a lot of the nods to the previous instalments were lost on me (although I'm aware of the main characters who I expected to crop up). That said, I thought the movie was decent, but no better than half a dozen...