The WSJ article specifically mentions that this relates to secured debt (mortgages), not credit card debt. Interest rates are fully tax deductible in the Netherlands, which incentivizes higher mortgage debt than in many other countries. Many people own homes, and the ones that do borrow the majority of the market value when buying.
Housing prices did fall recently (and are now headed back up), but they did not tank as they did in the US. Similarly, the rules on mortgages were on the whole much stricter than in the US; this, combined with the relatively low unemployment rate, resulted in a foreclosure rate which is the lowest in Europe.
The housing market during the crisis, and to some extent now, looks a lot like people stuck in the place where they live. They can make the mortgage payments just fine, but their hopes of swapping that starter house for a larger one have been put on hold until either they build up more equity or the housing market improves.