Yes this is a big oversight and one Google would be wise to correct sooner rather than later, LOL.
For those annoyed at having to confirm on screen before it will dial, trying using the voice search instead (long press on the magnifying glass soft key or run it from the widget or app drawer). This one will offer on-screen confirmation of the match, but will dial automatically if you don't tap the confirm dialog on screen.
On the voice dial, no matter how i say it, be it "call <contact> at <location>" it only ever gets the contact and then I have to choose on screen the right location be it home, cell, work, etc. If it does match outright, for example the contact only has one number listed, it still will NOT dial automatically.
The voice search though, will dial if it finds the match outright. Just wait for the confirm dial or try again prompt to time out.