Bankish: You're very clearly a big fan of Cdn banks and rightly so. I thought I'd try to answer your question and also provide perspective. 
The JH dividend growth portfolio was established on 09/13/12 and shos a 64.5% total return. Using longrundata.com, a portfolio of Canada's six banks, equally weighted from the same date would have returned 85.2%. So you are correct, a bank-only portfolio would have outperformed. Case closed. 
However, when I look at an investment portfolio, I personally prefer to assess it not just on its return but also its level of risk. The best and easiest way (at least for me to do this is to take the stocks currently held and see how they performed in the last major bear market (I use 07/19/07 - 03/09/09 for calculation purposes. Doing this, JH's more diversified portfolio would have dropped 30.2% while your concentrated six-stock bank portfolio would have fallen 49.7%. (BIP.UN was excluded as it did not trade during this period) 
Might be of interest.
SFI