Flag Flying in Scandinavia

Slowly, as time permits, I am studying the works published in the XIX ICV Stockholm Proceedings. I was reading Tom Bergrot's report on early Finnish flags when I came to a paragraph that made me think. Namely, we are all accustomed to the fact that the general population flagging in all the Nordic countries is very popular and a matter of of course. The early adoption dates of the national flags of these countries make us think (at least I felt so unconsciously until now) that it was a normal practice accustomed for ages in these region. However it was not. I am quoting Tom:

In Denmark and Sweden the national flags were considered belonging to the king and the authorities. In Denmark efforts were made in the early 19th century to introduce flagging as a common people's right but this was prohibited in 1834 and then again permitted in 1854. In Sweden the national flag[s] were seen as a distinction of the navy, the castles and the fortresses and only in 1870's the Royal Castle and the Parliament began to fly the flag. Yet at the end of the century the national flag was rather unknown in the countryside Sweden. Both in Sweden and in Finland it is remarkable that the increased use of flags in the late 19th century in both countries is in some way connected with the summer tradition