> (2) Your expectations as a reader partially determine your judgement as to how much value a book has. As your expectations increase...

I understand this to mean that my ever-improving taste might make it seem like, as time goes by, a greater and greater proportion of books seem to be of low quality. However, it works the other way around, too: As people through new generations become ever more easily satisfied with mediocre writing, the need to produce high-quality works decreases. At least, this is what I think is happening with TV.

Good point. I think both can be happening simultaneously.