At first, the DIN is a private organization, in terms of a trade organization. It is only partly founded by the government. It is the same like the ANSI, NIST, and SAE in the US (they are called National Bodies), or like ISO, IEC, ETSI, CEN, and CENELEC on international and European level. I am on of the experts who in that field for electronics and safety in electronics. I am in several working groups within almost all of these organizations. Even I as an expert who is working on those documents, I have to sign a away almost exclusive to give away all the copyright to those organizations. That said, even I have to buy and pay for those standards, even as I have access to preliminary versions that I had to work on, to review, and to comment on.
The standards published by all these organizations are standards and NOT laws. If you have very good reasons you don't have to follow those standards. But then of course, you have to have good reasons.
The EC (European Commission) mandates in certain areas, that a so-called harmonization has to be done. That is e.g. in the area of wireless communication a regulation in the 2.4GHz frequency range. As all telecommunication related topics are standardized by ETSI, the ETSI gets a mandate to work on this topic. Then companies like Cisco and IBM work on this topic and publish a standard, which then becomes an EN and then is approved by the National Bodies, namely DKE in Germany, to become a DIN EN. Then EC publishes in its directory that all wireless communication devices within Europe has to follow this so-called harmonized standard. If your device does not follow the requirements of that standard and something happens, then you become liable and it is your task to prove that you weren't the cause, which becomes hard if didn't followed the standard.
The very same procedure is true for safety in machinery, another topic I am heavily involved in.
That means, the government has laws, that e.g. in safety in machinery, that you are liable for your machinery you put in production. Then the government has a list of standards that is published, because experts like me said: if you follow those standards you will be in line with the law and you have done the best known to the current state in technology to prevent accidents.
That said, you don't have to follow those standards if you have reasons to do so. But it makes your life easier if you follow those standards.
TL/DR: Those standards are NOT laws. Those standards are protected by copyright. Because selling these standards mainly finance the infrastructure to develop these standards. This is not paid for by the general public like the government itself.
"The DKE business organization finances about 95 % of its budget from the proceeds of standards prepared by the DKE and sold by the VDE VERLAG and Beuth Verlag.
The remainder is contributed by the union of sponsors, which has about 400 member companies, five associations of the electrical industry and nine associations closely connected to electrotechnical standardization."
That means, if you would like to abandon copyright in standardization, then the general public has to pay with their tax money for that.