Fabian: are you being purposefully ignorant? I'm not saying those decks are generally fast, but that if they can be made fast, then yes they can work. For instance a feast, chapel, highway, and sab sets up long before chancellor/stash gets out of range. Likewise, menage/remake
Why is this so hard? Chancellor stash is a solid combo that will eventually win a lot of games. However, if there is something that can be set up quick enough to reliably disrupt it - like a TR/ minion engine, like a draw engine with margrave, or like scheme/golem/possession then it will be weaker.
It takes a while to setup chancellor/stash, other stuff, particularly chapel decks and reliable discard engines can be fast enough to counter it.