I live in Norway, where owning your own apartment or house, is almost seen as a universal right, and there are very strong tax incentives. Renting an apartment or house is very rare. Most people in Norway spend a lot of time indoors, especially during winter.

I believe the most important arguements for incentivicing people to own their own house or apartment are:

 1. You do not need to ask for permission for modifying your house or apartment, as long as it's within building codes. This includes any modifications you yourself need or want, even if it would reduce the sales value of the property. 
 2. There is no need to fight the landlord to get him/her to fix broken things, paint, or do cosmetic changes. You can simply do so yourself whenever you want, or when you can afford it. 
 3. Any improvements you do will benefit yourself, and not the landlord. If you do improvements, you get a higher price when/if you sell.
 4. Being able to do modifications without asking for anyones permission, means you don't have to move to another house or apartment as often as if you couldn't change it. 
 5. When you pay your mortgage, you are saving for yourself. When you pay rent, you save money for the landlord.

The first four arguments are mostly about quality of life for individuals and families. But having properties properly taken care of by interested owners, will obviously be positive for the society at large too. 

The fifth argument is the most commonly cited argument by Norwegians, but probably mostly makes sense from an insider perspective, where the incentives already are in place. I do not think it is a particulary good argument for changing government policy (but I do believe the first four are).