Damn you got really unlucky. My experience with 5 keys is about 1 resplendent in every 3 or 4 troves, which is still low. And sure, skelly keys are cheap to craft, but as with dynamite, people will probably use the altar slots for something else more potent.
Edit: By the way, I didn’t notice it during my tests, but apparently Soul Echos are bugged: [1.3.0.8] Ascension Altar's "Faster Nemesis Spawns" works incorrectly