You were being "punished" in that Chinese passive-aggressive way, for being Norwegian. The Chinese gov't is still harboring a big grudge for that Peace Price. If you had been a Finn, you'd have gotten 30 days even if you only needed 10.

There are indeed some Chinese Embassies and Consulates that will only take visa applications from citizens of that country or foreigners who have long-term visas and/or residence. The Chinese regulation stating that has been on the books for a long time, but has been selectively ignored for many years. In the past couple of years, many Chinese missions are tightening up--whether it's because of some order from Beijing or whether they just want to cut their workload rather than earn visa fees is unknown. The Consular Head of the moment generally has a lot to say about how s/he wants to implement the regulations locally. Example: used to be easy as a non-resident traveler to get a Chinese visa in Vietnam; in last 2 years, practically impossible in Hanoi and only with difficulty and via an agent in HCMC. Phnom Penh was free and easy for all comers until about 3 months ago. Berlin, Germany won't accept applications from non-citizens and non-resident foreigners, though not so long ago, they would.