OK, that may be a bit harsh. But the danger is that a translation that is out-of-date or badly done will turn you off the book. Many classic books whose translations are now beyond copyright are available for free. But these translations are, generally speaking, poor. To really appreciate these books, find a translation that is up-to-date and that suits your reading style.
It's also worth pondering whether the newer translations are riding on the coattails of their denigrated forebears—"would this have been as well-received and become a staple in the English-speaking world if the newer, purportedly better translation had been the only game in town from the beginning?"