Excellent questions:

A) Yes - at about hour 6 I asked one of the FA. I had developed a good rapport with this attendant during the earlier dinner service and during the mid-flight service I casually mentioned that the light had remains illuminated continuously for the past 6 hours. I was given a steely stare and a terse response - 'we don't control that, that is controlled by the pilots'. I did not press on the matter given the tone and manner of delivery of this information as it would not have been productive.

B) Yes, some other passengers were up anyway.