> The squatting thing is seen by many as a measure against speculation on living space and at the same time giving young kids a cheap place to live and get on their feet.

This is true for abandoned empty buildings. If the owners are not using a building and someone starts to live in there, they are allowed. The idea is that the right to housing is greater than the right to own empty buildings just for speculation.

In cities were housing offering is lacking this is seen as a measure to push speculators to sell or rent their properties.

this was known in the US as "squatter's rights." unfortunately it's mostly vestigial now.