this is a fascinating discussion. i think reading is definitely a form of escapism, however i would argue along with several others here that that is a very positive thing and in fact necessary to some degree, and what distinguishes us (as humans) from other animals ; our ability to think abstractly. this is what has allowed us to create great works of art (in all its forms) and technology ; it's what allows us to speculate on the origins of the universe, explore the structure of the atom, create entire new worlds in novels and in our imaginations.
several other posters have touched on this notion of abstract thought and creation and it has reminded me of a book called "Less than words can say" by Richard Mitchell, which is available here thanks to Madam Broshkina in
lrf and
mobi format.
it doesn't necessarily speak to the original question (is reading a form of escapism) however it does talk a lot about the power of language in making abstract thought possible at all (and escapism relies on abstract thought, as do all forms of creation ; i would argue in fact that escapism itself is an act of creation, since you are "creating" an alternate reality in your imagination ; however much this is guided by the ideas of the author, it nonetheless requires a significant participation by the reader to come to life). he says at one point
"If, for instance, there should exist something that a language has no way of expressing, then that thing does not "exist'' for the culture that speaks the language."
Given that reading is arguably the best way of becoming exposed to new language and that by its nature it encourages abstract thinking (another point made by Mitchell, in fact he postulates that without writing structured thought is more or less impossible), immersing oneself in a book not only allows us to escape into the creations of others but also gives us the tools to imagine new things ourselves, in the form of words and "pure" (that is, non-materialised) ideas. without reading (and before that, storytelling, and before that, the invention of language) we would not be where we are today, as a species. all revolutionary thinking (the world is not flat ; the earth is not the center of the universe ; every material object including living things is made up of billions of microscopic particles ; etc.) relied not only on our ability to observe phenomena, but more particularly to extrapolate from our observations, and this extrapolation is not possible without language.