What I am seeing in the various replies and in the links provided is that people really don't know exactly what a constitutional monarchy is or what the monarchy's roll is within that constitution. So I have to ask, how can one argue against something when they really don't know what it does? Case in point, this link that was provided:
19 Foremost Advantages and Disadvantages of Monarchy | Green Garage
This link does not apply to Canada at all.
The next link:
10 Things the Queen of England Still Does for Canada | Mental Floss
This is VERY simplistic and get's it wrong from the very beginning. Our head of state is the Queen of Canada, not the Queen of England. There is a distinct difference, even though the same person fills both rolls. The implication is, that England still has some say in how our government is run and that could not be further from the truth.
In that same write up it states that the Queen appoints the Governor General and the various Lieutenant Generals, while this may technically be true, realistically it is not. The Government of Canada recommends someone to the Queen and that person is then appointed by the Queen. It has been many many years since the "Crown" appointed a GG that was not a "recommendation" by the sitting Government of Canada.
I assumed everybody knew that....
Guess I was wrong!