Perhaps it was one of the measures to make life "difficult" for Czechs after assassination of Heydrich.
How did the prohibition of sexual intercourse with persons of German blood make life "difficult" for Czechs? There were plenty of other races for Czechs to have sexual intercourse with if they found it difficult to abstain.
Also, I note that Greg Singh has omitted some essential parts of the document.
The option of germanisation was not available under the following circumstances:
1. The Protectorate national demonstrated an anti-German general attitude, particularly if he had been already come to unfavourable notice for political or criminal reasons.
2. He had initiated intimate relations with a married German woman, particularly a soldier's wife.
3. He had seduced or raped an under-age German girl.
I presume that Greg Singh would agree that some form of punishment is appropriate in cases where a man has seduced or raped an under-age girl.
The document also states that the Protectorate national is not liable to punishment if the German woman he had sexual intercourse with was a prostitute, the justification being that sexual contact with a prostitute did not endanger the "racial health" of the German people or cause public disquiet. I guess that ruling was consistent with the general attitude toward sex workers in that age, namely that they were excluded from society and were "fair game" for any man to have sexual contact with, and did not deserve protection or consideration.
Another interesting feature of the document is its statement that "germanisability" does not depend on "racial-biological" criteria alone, but also on other criteria, such as family background, character, and political reliability. It makes the ruling that if the Protectorate national is not worthy of germanisation, then he cannot be regarded as "germanisable"; presumably that means that the negative non-racial criteria outweigh favourable racial-biological criteria, although that is not explicitly stated.
If the Protectorate national is judged to be "germanisable", then marriage with the German woman is to be considered, in accordance with the existing regulations for marriage between German citizens and Protectorate nationals.
If the Protectorate national is judged not to be "germanisable", his delivery to "protective custody" in a concentration camp does not automatically follow, but is to be applied for only if the Stapo office dealing with the case considers the applicable three-week prison sentence to be insufficient punishment.
Where the Protectorate national is subjected to measures by the Stapo, the German woman concerned is also to be subjected to imprisonment or "protective custody".
Finally, it is noteworthy that the document was issued by RSHA office IV D 1, which was the Stapo office responsible for combatting opponents of the Reich
in occupied territories. That suggests that the RSHA regarded the Protectorate of Bohemia-Moravia as being an occupied territory rather than as part of the Reich.