[peter12]

The biggest reason for the GG is to ensure smooth transition of power between governments. For that alone, the institution is priceless.

To have an institution so far removed from practical politics, but one that normatively (and subsequently) enjoys a great deal of trust as to its impartiality is imperative in a democracy like Canada where the executive function is not separate from the legislature. That is, our Prime Minister is selected from the ranks of the House of Commons.

In the US, the President is hypothetically supposed to balance the powers between the legislative and judicial branches, but enjoys so much popular support in his single person that Presidents can break that balance by challenging norms that were previously unassailable - ie. the veto.

The point is, democracies usually need someone like a referee to make things fair, smooth, and non-violent. As Cliff said, an unengaged, almost useless Crown has been the best choice for almost every single functioning democracy.