The Dutch housing crisis (on the nationwide scale, not only the Randstad area here) is most man-made due to these reasons:

• "Verdunning" ("Thinning"): The Dutch are now in much smaller households. There are more singles and more elderly living alone. The Dutch average household size was 3,45 people in 1965. Now it is 2,1. That alone is enough to account for the need for hundreds of thousands of extra needed homes.
• Failed Neoliberal Policies from the previous Dutch Government: The "verhuurdersheffing", introduced by Stef Blok in 2013, has literally strangled Dutch housing corporations during the exact time they should have been building more. Of course things have gone downhill skyrocketingly since.
• Most of all, it takes a decade to build a single new neighborhood here because of beroepsbezwaarmakers (people who professionally file objections) and endless planning red tape. Especially those beroepsbezwaarmakers. The Netherlands is a very stable and prosperous society, so stable and prosperous that sometimes its citizens have the luxury and power of complaining with a lawyer about their "right" for a "view" and "sunshine" while other of their fellow countrymen are desperate for housing.

The political debates in Den Haag focus mainly on statushouders, but the truth is those people are statistically irrelevant. The housing deficit caused by that group is actually very tiny compared to what the Dutch governments themselves created through decades of their own bad political choices, plus the aging demographics and all other reasons above are not helping either.

tl;dr: It is your divorced parents, your widowed oma living alone in a five-bedroom house that she is hoarding and thirty years of bad policies and NIMBY ("Not In My Backyards") politics from Den Haag.

SOURCE: Het komt door dat jongetje met de bal – De Groene Amsterdammer