Deaf children can be, and some are, LITERATE, in ASL. Unfortunately, in our present society in the U.S., English is deemed as "The language" to learn.
One can fully function in the United States without English. It's a foreign concept for many people. If a child learns Spanish as a second language and can use it with minimal conversation skills, we often jump for joy at his accomplishment. Yet a deaf child who is fluent in ASL and can use basic English, as his SECOND language, is told to do better. That's hypocritical...and unfair. Especially since often there isn't a formal assessment for ASL in place to show his true literacy skills with his FIRST language.