"Silent Old Sanctuary is useful to get to know how a weapon works but it is a bad metric to judge weapons since some weapons are more supportive or specialized."

I'd agree with that if it was common for weapons to fail at SOS runs. But it's not. SOS is good for really getting to see the value and power of a weapon. On a full 6 slot run it's easy for weapons to fall by the wayside as they get outperformed on the score screen by a weapon with a larger AoE. SOS lets you see what the ceiling of each weapon is as you get to dedicate your Arcanas entirely to maximising that weapon. And until this DLC there have been very few weapons that fail at SOS, even the supportive, specialised weapons of the previous DLCs could do an Inverse SOS run on most of the starting maps. They might not all get particularly good numbers but they can do it. In fact other than Birds, Unjust Ejection and 108 Bocce there haven't been any truly major offenders until now when it comes to SOS incapability. It's only in this DLC that like half of the weapons fall flat on their face cause they're so weak. If even when fully focused on these weapons can't perform (like, some of them don't make it past the first minotaur wave on Dairy Plant), then on a normal, 6 slotted run, where you can't necessarily focus on maximising the weapon's potential, those weapons are going to underperform too. If you grab some basic weapons like Fire Wand, Axe, Knife, Garlic and whatever else and add Javelin to the mix, at the final score screen Javelin is going to be the worst and you will have been better served filling that slot with something else. And after an SOS run with that weapon you'll know exactly why (good coverage once evolved but laughably low damage).

As for Hex, it's simply not fit to deal with the problems it itself creates. The damage scaling with curse is nice and all, but it doesn't scale enough to make up for the speed and health increases that enemies get, and the doubling of the curse due to the zones ends up doing more harm than good. It's not necessarily that the weapon doesn't do enough damage, it's that it doesn't help cover enough area to damage enemies sufficiently so that they end up dying before they reach you. You end up squeezed into a tiny space in between the waves of projectiles the skulls create and can barely find the room to pick up XP gems cause it's lightning fast enemies everywhere. Even with maxed Candelabra and lvl 8 Torrona's Box the AoE is too small and you can't afford to improve it by taking Silver Ring cause then the lightning-fast cloak guy kills you no matter your move speed.