Do you understand what the whole point of MMA is? It's about taking what has worked in the past, refining it and applying it succesfully in a fight.
If we all followed your logic then we'd still all be doing karate kata under Fred Ettish like instructors. Just as BJJ's exposure in the UFC changed the way people viewed martial arts before Eddie's approach is changing the way people view no gi grappling in terms of positioning and control. Whether you like it or not, the guy is adapting BJJ to be better suited for MMA and he's very innovative.
Eddie set up the submission when he had his opportunity and Royler, despite his best efforts, couldn't avoid or escape it using any triangle defenses. That isn't luck. That's applying a technique effectively.