Three phase being what it is is strictly a management decision.In Canada having 3 phase wiring is strictly a commercial or industrial option.
While the 2 phase wiring is standard for residential. This allows 110 volt single phase and 220 volt two phase appliances.
Having used single phase, two phase and three phase wiring there are advantages to each.
Really doesn't need to be that way but getting the management to understand the advantages of being 'like the rest of the world' is a very very difficult position!!
I'd like to hear what the advantages of each as you see them.
(I'm seeing not a lot of advantages to our present system except that its legacy and that makes it 'cheap' but its sure not helping our competitiveness!!!)