The trouble with bringing the nation closer together federal policy-wise is that regional interests simultaneously want national buy in and decentralization at the same time. The Liberals tend to favour centralization or harmonization as do I; however, this raises fears of national power and wealth concentration. Fears that I would argue are legitimate.
The problem if anything is that we have a scale-issue that have evolved over time (from a predominately rural to predominately urban country in the context of a globalized information economy). Provinces are almost an anachronism.
As to fears of wealth concentration - only the national level of government has redistributive powers to make a difference nationally on that issue. Decentralization leads to precisely the opposite outcome - and I'd argue is one reason why we are dealing with the headaches as a nation right now.