I would say that, yes, people did once sit and pay attention to the singular entertainment source for the duration of the program. I remember when I got into audio and joined the social group interested in it we would get together for listening parties and play entire albums without a single comment and everyone made every effort not to distract anyone else. Even when the LP was being flipped over to hear side two the room was dead silent. Until the full album had played all the way to the end, people were paying attention. The same for early HT systems. We would stop everyone and watch entire movies, usually on Beta with HiFi soundtracks, and later on LaserDisc. We were into the hobby to experience the recreation of someone's hard work, to appreciate the creativity of the artists who make music and movies.
Today very few do that. At the last big get together I attended with this group I was trying to listen to some speakers, I mean really listen. I cannot think of a single track playing through without someone in the room talking, or moving around, or doing some other highly distracting thing to disturb my concentration. I don't think people have the capacity to really enjoy art anymore.
Charles Ives once claimed that art, specifically music composition, would soon become something every man could and would do. That it would become the people's art and the greatest symphonies ever conceived would be created in the minds of farmers and businessmen. That's one reason he refused to stop selling insurance when he could have made a very decent living as a composer and conductor.
Ives was correct! But the result is that we so inundated with new music, movies, TV shows, short video clips, and the internet that our choices have become too broad and we are afraid of missing one thing because we are focused on another. No one really sits and listens anymore - at least very few do. In fact, this goes well beyond just music and TV, we don't stop and pay attention to anything anymore. We read books in noisy places and start and stop in the middle of sentences. We play music on our earphones at the same time we are trying to navigate the dangerous streets on our bicycles or when trying to look masculine while that hot girl on the treadmill next to us notice how handsome we are. We don't appreciate music anymore.
I was working with my new friend and guitarist in my band on recording music. This guy has decades of experience and really knows the tools of the recording trade. However, he has never really paid attention to the music he loves enough to realize that there might be three or four acoustic guitar tracks on his favorite songs he would like to emulate. He was shocked when I wanted to use up 6 tracks to add percussion to a song until I showed him how several songs he loved had even more percussion parts. He never stopped to listen to the music. He just took it at the initial moment of hearing it and made up his mind and stopped trying to understand why and how and so on. Which would be fine except he wants to be a great songwriter and recording producer.
I see it everywhere. I teach drums to four kids and only one of them can listen to a song and pick out what the drummer is doing so he can attempt to copy their playing - so he can grow and mature as a drummer. The other three cannot even figure out what the bass drum is doing in their favorite music, yet they pay be to teach them to be drummers. I am about to fire one of them as a student because he refuses to do anything extra to learn, he practices too seldom, and he is wasting his time and money on this attempt to pretend he is a drummer.
That isn't to say everyone is like this about everything, but I believe it is much more common today that it ever was thirty years ago.