When I was a professor, one of the things that annoyed me most was when was when students failed to do assigned readings.
After teaching for awhile, it became painfully apparent to me how many students were blowing off the readings altogether, or doing them at the last minute. Only the minority of students regularly completed the readings for the days they were assigned. And many students read selectively, searching for material that might be on the exam, and nothing else.
The prevalent attitude that "the readings are a waste of time" makes me so sad. Students, the readings aren't busy work. Your professor can only tell you so much about a topic during lecture, but large amounts of material can be presented through a reading assignment. If you don't do the reading, you're losing the opportunity to learn a large fraction of the course material. Your grade will suffer, and you simply won't learn as much.
In addition, college level reading is an important skill. By not reading, you not only miss out on the material itself-- you miss out on the opportunity to build your vocabulary, reading comprehension, and writing skills. All of these are skills you will need in the workplace-- especially writing. In order to become an advanced level writer, you have to read lots. There's no way around that.
I know, I'm getting a little preachy, and I try not to do that. But the growing attitude that it's no big deal to blow off the readings really bugs me. Students, please make an effort to do your readings, and to complete them for the day they are assigned.