When I was referring to RNG in 5.0, I meant "if you got absolutely abysmal RNG to the point where Fireball was higher on your spell DPS than Pyroblast", RNG. And yes, if you got THAT kind of RNG, you definitely wouldn't be placing unless your fellow raiders were complete shit, or vastly outgeared you (and back then, my raiders were quite good; hell most of them still are, but that's beside the point
)
I said 30-50% was during 5.0. It's no longer the case, but RNG is still a great factor. If you don't see Fire's flaw in being super-heavy RNG, then you're the one who's misinformed.