My older daughter, a kindergartener, has to keep a reading log. Or, rather, I do. She is not physically capable of writing down the title of the book, the author, whom she read with (or who read to her) and what we discussed in the tiny boxes provided. So the fact that her homework is actually my homework is one reason I hate reading logs.
But the more important reason I hate them is that counting pages takes the joy out of reading just as counting calories takes the joy out of eating.
And counting pages (which some schools, but luckily not ours, require) misses the point. As my sister said at age 5, returning the book the teacher had given her in response to her request for more difficult books, "This book isn't harder; it's just longer." The length of a book is utterly unrelated to the difficulty of its vocabulary or complexity of its plot or its emotional resonance. It is unrelated to everything except the question of whether you should get the hardcover or the paperback (or, these days, the e-book) and whether it's too heavy to carry on the subway (for the Kindle- and Nook-less among us).
To mix my metaphors, reading is not a sport. It's not about how many pages you read or how fast you read them.
Reading is supposed to be fun. Or informative. Or both. And reading IS fun, when you don't feel like it is being spooned to you like medicine rather than dessert that you eagerly gulp down yourself.