Ninja nerfing via droprates is worse than straight nerfs to the builds

I totally agree with you, and I took a look at the people who didn't agree.

https://www.pathofexile.com/account/view-profile/DarthSki44
"Stop complaining you are talking nonsense" - 0 challenge done, perhaps this dude doesn't even play league at all

https://www.pathofexile.com/account/view-profile/Shagsbeard
"Go feed a squirrel" - 1 challenge done, maybe half way through campaign and get PWN'ed

https://www.pathofexile.com/account/view-profile/Isobar
"This is how I predict the price would go" - 8 challenge done, this dude is actually playing. I don't agree with his prediction as the drop rate has been nerfed to about 1/40 so based on supply / demand, I think ashes and omni will be as rare as HH level, but again, this guy actually plays the game.

And about OP, he's done 2 challenge so he probably didn't play much in league. My personally suggestion is that just don't use ashes or omni, there are a lot of builds are viable without them. While I agree with you, neither archnemesis nor ashes / omni is a deal breaker.