By the time we get to the Qing Dynasty era in Jin Yong's stories, wulin in general had degraded considerably from what it had been during the Sung, Yuan, and Ming eras. Old school sects such as Shaolin, Mo Dong, and Ngor Mei were still around (and probably so was Kunlun and a few other venerable old sects), but didn't seem as active or as influential as they had been in earlier times. In fact, the entire infrastructure of old wulin seemed to already be giving way to more modern societies and organizations.
The Divine Dragon Cult really stands out in DOMD because it's the closest thing we see in the story to an old school wulin sect, with its intrigue, rituals, hierarchy, etc. The Divine Dragon Cult would not appear out of place in a story such as DGSD, LOCH, ROCH, HSDS, or SPW, but does seem oddly out of place in the story in which it actually appears, DOMD. In DOMD, the Divine Dragon Cult almost felt like an anachronism compared to more "modern" organizations such as the Heaven and Earth Society, which resembled modern day Triad type underworld organizations than it did old school wulin sects.