NBC, already under fire over which Summer Olympic events the network covered and when it fed the coverage, ended the games on a sour note for many by pre-empting Ray Davies of the Kinks performance of Waterloo Sunset and deciding to delay showing the Who medley for an hour so the network could run the pilot of a new sitcom and local newscasts.  The fact the sitcom (Animal Practice) was even worse than a number of the pop acts the network did televise during the ceremony only made matters worse for NBC.  One Twitter user tweeted 'Doing a Twitter search for Animal Practice right now is like tapping a keg of pure hate.'
The backlash wiped-out any points the network and event organizers scored with viewers for the unannounced appearance of Brian May and Roger Taylor of Queen and the unannounced but widely expected (story) of Nick Mason of Pink Floyd accompanying Brit pop sensation Ed Sheeran on Wish You Were Here. 
Organizers were unable to convince the Rolling Stones to appear during the opening or closing ceremony and it is reasonable to assume a number of other top UK Rockers were asked to participate but declined.
HollywoodReporter.com