There are many different aspects of their society that result in lower home ownership. One...well...they lost a lot of stuff in WWII...so apartment blocks were built to house the people. Thus, apartments became the norm in the city. Berlin is a renter's city...there just aren't many single family houses. Now...some of these apartments are amazing...as in any great city. And the percenatge of home ownership outside the cities is close the US figures...
And...like you mentioned...a different attitude regarding homes as investments versus...well...homes.
"The acute housing shortage lasted well into the 1970s, so apartment blocks and multi-family dwellings went up very quickly," said Just, who added that renting has been historically far more attractive than buying. "Though high demand forced prices up, rents remained very stable and affordable. That the landlord was often the city or some public entity implicitly meant that rents were subsidized, and below market value."
Unlike other Europeans, most Germans live in apartments rather than single family houses, where home ownership rates are much higher....
...Real estate experts also predict that home ownership rates will rise simply because of a shift in demographics, as the war generation, who were mostly renters, dies out. Among middle-aged baby boomers, almost 60 percent are home owners and favor a suburban rowhouse with a garden and white picket fence...
..."In the US, a house is a commodity," he said. "You buy your first apartment as a single, then sell and buy a bigger one when you are a couple, then upgrade to a house when you have kids, then move to a condo when the kids have left home.
For Germans, a house is for life, so they invest their soul and a lot of capital into this one house. Germans haven't learned that houses have re-sale value."
http://www.dw.de/dw/article/0,,2155971,00.html