High amount of RNG is mostly a tradition of American tabletop game industry that had been carried to early video game industry. Tabletop games from other places may use less RNG, there is a more deterministic class of tabletop games called Eurogame, for instance. Just because many old-school hardcore RPGs (that have been influenced by American tabletop games such as D&D) use a lot of RNG, doesn't mean there is anything inherently hardcore about it.
I think the disconnect is when you base the ENTIRE game around "American tabletop game" as you phrased it, then throw out these Japanese RPG style static (and huge) damage numbers and stats, it is very jarring. Pick a design philosophy and stick to it! If we are going to be arbitrary why not 100 in each stat to match the inflated vitality, armour, etc?
I know this wasn't your exact point and you were more about the RNG but they are related in that they seemed to cherry pick multiple design strategies and smush them all together, but not necessarily in the most coherent way. I think a couple of patches will resolve the issue, IMHO. It is not as "we r DOMED!1!!" as many are making it out to be.
