I am compelled to ask you the same.
I find this the least convincing of all the arguments that I have seen thus far. Where is the distinction between your statement and 'English is an ORAL/AURAL language. (PERIOD)'? All oral/sign languages are symbol systems. All writing systems of oral/sign languages are symbol systems of symbol systems. I fail to see how the modality of the first system could/should prevent the second.
I propose that you learn it naturally. Or at least as naturally as would any native speaker of a language learn the writing system for that language. The problems that are experienced when learning to read and write English are the direct result of not knowing English. Also, once you have learned one writing system, it is infinitely easier to learn another.
Just because something is hard to do doesn't mean that it shouldn't be done.
Thank you. I am honoured. Truly.