Most people certainly sat the entire evening in front of the TV 30 years ago. Even today old people sit over 7 hours a day in front of the TV since they haven't adapted to newer media yet.
For history you can see that about 30-40 years ago people watched 7 hours of TV per day, then it went up to 9 and now it goes down again as people start using computers instead. I don't think this is a bad development switching from TV to computers.