Even if they solve the regional dialect problem, there's still the problem of people being really imprecise with natural language.
For example, I may ask, "what is the weather like?" I could mean:
- today's weather in my current location (most likely)
- if traveling, today or tomorrow's weather in my destination
- weather projection for the next week or so (local or destination)
- current weather outside (i.e. heading outside)
An internet search would be "weather ". That's it. Typing that takes a few seconds, whereas voice control requires processing the message (a couple seconds usually) and probably an iteration or two to get what you want. Even if you get it right the first time, it's still as long or longer than just typing a query.
Even if voice activation is perfect, I'd still prefer a text interface.