A disowned former hive prince, and the weakest of the worm gods Doesn't excuse them being strikes though, but year 1 was bad, worse than this year imo, this year they have a very small budget, and dwindling support from Sony, then they had Activisions full budget and studio help, they had no excuse

The lore reason is that both were basically rejected by the rest of the Hive by the point we faced them: Nokris was disowned by Oryx for the sin of necromancy (because necromancy is basically a bypass of Sword Logic, at least in Oryx's opinion); and Xol was in hiding because he was scared of his bigger brother Yul (for good reason, as Yul was planning on eating Xol). Both were cut off from the main tithing hierarchy of the Hive, and received tithes only from a small cult, the Grasp of Nokris; and in this state of being a minor military power, they decided to try to conquer Mars AKA pick a fight with Rasputin, the closest thing to a machine god humanity could build. Honestly, they were lucky that Rasputin just froze them over instead of dropping Deimos on them or something.... Basically, we finished them off after they got booted from their families with no parting gifts and then lost a fight with Rasputin. Non-lore reasons have already been covered by other commenters. Chances are the lore was refitted to make them even weaker than intially planned just so they didn't have to be a/several Raids or Dungeons.....

To cut development costs. They wanted two new strikes so they copy from two quests and called it new strikes.