A home most certainly is not an investment, at least in the conventional sense.  Buying a home is nothing more than prepaid rent to be amortized over your life.  Sure some homes can be bought and sold in a manner to yield gains.  But those gains can only be utilized if you are able to unlock them.  So unless you decide to sell and rent, downsize, move to a cheaper location, or take in tenants your gains are not accessible.  Most people who choose to own their own house do not seek out those options.

As a result in most cases the mortgage expense should be viewed as a household expenditure (i.e. prepaid rent), not an alternative investment option to conventional fixed income or equity based investments.