I think that's because we're in the very early stages of a transitional period. The end goal is something like the Star Trek computer, free-form natural language queries ending in desired actions. I think this approach of filing off all the rough edges (namely, handling every possible unique way of phrasing a specific intent) is a dead end.

What we have nowadays is more like a voice-input command line, with all of the stiltedness and attention to detail when crafting your input that requires.