Ed,
I've just returned from out of the USA.
The answer is that you have to think data packets sand not just electricity. That's where is the fundamental difference between using a terminal block or a wired buss.
OK, I'm not trying to open a can of worms, but explain this in a little more detail. I am a retired IS/IT guy with lots of complicated networking under my belt. A terminal block is no better then a hub, plenty of data collisions. That is why we went to switches, less data collision and higher speed. In my mind a bus is a bus. A terminal block, like I said is a short bus, the runs to the various drops can be greater than a standard bus with short drops. Factors such as resistance and impedance can all effect data loss.