To a certain extent PTravel has answered his own question, by describing the limited usefulness of bad IFE it explains why some passengers are interested in good IFE.

On good IFE there is a genuine variety of movies and no, they're not edited. On good IFE the music isn't some naff radio stations but instead is hundreds of albums where you can build your own playlists which you can hear because tou have decent NC headphones. Most importantly good IFE is AVOD so you can watch what you want when you want and pause when required.

While that tends to be mostly available on international flights with a bit of thought good IFE can be deployed on short flights as well. As an example on the 1 hour domestic flights I'm on regularly having an up to date subtitled news bulletin works pretty well (and better when the show following it is top gear). After spending a day at a client and rushing back to the airport it's nce to be able to sit back with a glass of wine, put the ipod in and catch the news. It's not fancy but it's a well thought out IFE solution unlike giving passengers the choice of 6 kids movies on a 9 hour flight.

My main entertainment on flights is books and ipod but I certainly do also enjoy the IFE, just not when it's 6 crap movies on a crappy 7" screen which is why IFE is important to me. (that and I'm a crap sleeper on flights and are usually travelling with a work laptop I don't want to fill with personal stuff)