I've had similar thoughts as well. One problem, it seems, is the amount of effort it requires to argue in this way. If you don't know your opponent's position backwards and forwards, it can be very difficult to come up with a line of retreat for them to follow. If you don't actually grok your opponent's position, pretending to do so is unlikely to be effective. Ultimately, it probably pays to specialize a bit in a couple of areas so you know everyone's argument well enough to find those lines of retreat and to help them intuitively understand your argument.