Holland is basically the "beacon of Protestantism" but not in the sense of the true religious sense of it, but more like within the "ideals" of it ie. the "ideals" of individualism, freedom, and the right to choose, if you get my drift?
I get it. The 19th and 20th century Calvinists reallt did not want any government involvement. There was a process of liberalisation againt the state, but also an internal movement into very strict orhodox religion, based on the reformation.
That finally led to an extremely orthodox protestant population (the European Bible belt) that's still influential, but also to the opposite liberal tendency starting in the 60s. It's what you see happening to people who grow up in this bible belt: they either join the Calvinism or drop out completely. There doesn't seem to be a middle.