Uh, how the hell is one supposed to learn to write? It is done by reading. If you read well-written books, there is of course no guarantee you'll become a good writer, but you'll certainly have an advantage.
People who are not exposed to good writing cannot write well. Obviously this doesn't mean one has necessarily to read fiction to write well, as there are many non-fiction books that are excellently written, but fiction is where you'll generally find the best prose.
As a rule, people who don't read good books are terrible at writing. I don't see how that can possibly be described as "utter nonsense" as it is pretty much self-evident.