If you think that "sounding smart" is pretentious or elitist, I offer two arguments:
- What is the opposite of sounding smart? Sounding stupid. You don't want to sound stupid, do you?
- You don't have to use the book to sound smart; use it to listen smart. The idea is to learn and understand the meaning of the words, not necessarily to speak or write them yourself. Other people use these words, and there's bound to be a word or two in this book that you hear often enough but you don't really know what it means, or it means something other than what you think it does, or you've been misusing it yourself. Rather than wasting time and cerebral bandwidth using context clues to figure out what it means, just learn the word so that the next time you hear it, you'll know what it means.