The main issue with language is that it's inherently necessary for communication. It may not always be spoken or written out, but we rely on various languages to convey our knowledge to others. Without some form of language, your thoughts are trapped in your head, so language is crucial to inform other people of your thoughts. If the language you're using is flawed, your capacity to convey knowledge is severely limited. This goes both ways. If the language offered a people doens't sufficiently cover a topic, then that people cannot recieve each others thoughts on that topic. More importantly, you use the language you are taught inside your own head. You rely on it to solidify your own thoughts. If you don't have the words to describe something you are thinking or feeling, you cannot even communicate that thing to yourself. Knowledge relies entirely on language to communicate it. With flawed language, understanding becomes immediately flawed.
For these reasons, it is crucial to have a wide enough variety of words to describe everything, or you will not be capable of understanding everything. Syme is absolutely right when he says that "not a single human being will be alive who could understand such a conversation as we are having now." If the government imposes limiting language changes, and they, over generations, take hold, future generations will not have the words to express themselves, to others and to their own selves. Listening to people speaking in regular English, to those who have never learned anything but Newspeak, would be like an anglophone listening to someone conversing in fluent Farsi. Language is a crucial component of knowing, becuase, if you're deprived of the words to explain something to yourself, you have no way of ever understanding it.
