I think that type of phone was everywhere because the national telecom provider (PTT at the time) handed them out with a subscription plan? I remember seeing "property of PTT" stickers on them.
Those were not handed out, you paid 1,50 guilders per month to rent them.
Also, you didn't have a lot of choice: until the end of the 80s it was officially forbidden to connect any non-PTT sanctioned telephone to your line.
