Has nothing to do with TV audiences in specific countries, otherwise why wouldn't Russia and Turkey have more sides in the CL? UEFA want to make money, however in order to do that they need to maximise it's appeal and audience. So the chances are they've got the balance right.
The romantics want to see Red Star battle it out in the CL final like the good old days but the reality is the same romantics will be the first to turn off after Madrid go 4-0 up in the 1st round. Or in the event that Red Star get lucky and draw Anderlect, then the romantics wouldn't bother tuning in at all, neither would anyone else.