Words, in English

I came to a rather disconcerting and disappointing realization this evening.  We were driving home and my nine year old son asked my wife why she cut her hair.  She replied that she didn't, but instead had the lady at the parlor cut it.
She misunderstood his question. 
It then occurred to me.  One sentence can be spoken, with an emphasis put upon different words, and the question contained therein can have multiple different meanings. 
One can say,  "Why did you cut your hair?" with an emphasis upon "you", asking why YOU did it. Or with an emphasis upon "cut", asking why you "cut" it. Or with an emphasis upon "did", asking for the motivation behind cutting it.
This realization really bothers me, for it reveals a serious inadequacy in the English language.  Our vocabulary and grammar are far too flexible in allowing this sort of ambiguity.  We cannot simply rely on words to communicate.  We must rely on inflection and tone to sufficiently pass our meaning.
Either that or we must genuinely master our vocabulary and grammar, perfectly choosing just the right words.
Unfortunately, our culture is going in exactly the wrong direction.  We are moving away from literary articulation, actually reverting back to an image based culture, like Egypt and hieroglyphs. If you disagree, stop and look at your computer desktop.  It contains a high majority of little pictures, called icons. Unfortunately not the religious kind.
I've been working toward verbal articulation, for years now.  And just now I've figured out a justification for doing so.