Take in mind that the post shared here is written by a company that provides listing services.
Housing is more of a right in Spain than in other countries, and at least in Catalonia, there is precedent that it supersedes property rights.
If your revenue is not enough to pay for an housing under regular contract but a shaddy owner allows you to pay a rent for the place so that he can bypass a number of regulations by pretending he has no tenants, would you choose living in the street or a car or would you accept it, hoping it is a temporary situation?
Most people would choose the later hence the way the laws are written. Landowners are usually the wealthy ones, so the less at risk of suffering.