I'd challenge you to transcribe a casual conversation without understanding. Too many words sound very similar, if not identical, and the context of the conversation dictates which word is in play.
Even something simple like "They're unhappy, Ness" could be interpreted as "Their unhappiness" unless you know Ness is a person in the converation.
That's like saying because "O" and "0" have the same shape that we can't solve OCR without general AI.
A modern statistical speech recognition system has no trouble determining that "they're unhappy, ness" is a dramatically less likely word sequence than "their unhappiness".
edit: I read your example backwards, but still, a statistical system can easily incorporate contextual words without actually understanding what they mean. Names from the speaker's contacts in particular are widely used in ASR systems for this reason.
That's because it doesn't care, it just goes for the most statistically probable phrasing in a general conversation, not the one you're actually having.
As for the OCR problem, try writing one for Chinese calligraphy and get back to me on if context is important or not.
Even something simple like "They're unhappy, Ness" could be interpreted as "Their unhappiness" unless you know Ness is a person in the converation.