You can gear for str/dex very, very easily. Especially at hero. I'll agree this can be a much more difficult task at level 20-40.

But if you're a class without damage reduction, your largest concern isn't going to be killing a dagger spec or worrying about stat loss. It's going to be bloos loss. And I am speaking from the dagger spec side of things (recently played Vyborny, and played Noelani and Yvalthras in the past). Blood loss won me a lot of fights I probably shouldn't have. The only characters that really stood no chance against me as a dagger specialist, are Orcs and non-berserker warriors who wielded heavy weapons (axe, mace, polearm mostly), and thieves. All mages have damage reduction to deal with blood loss and don't have to worry as much about stat loss as melee classes. Paladins and shamans can heal themselves and survive blood loss, not to mention sanctuary. Rangers can use staves and scrolls (for the most part) and have herbs, so they don't have to worry as much about blood loss.

Look at any dagger specialist PBF. The majority of their wins are going to be against warriors. Why? Blood loss.

I don't buy into the stat loss argument.

Also, there was a cloud giant sword spec who came and killed Vyborny in the Forbidden Forest for some reason. I never even touched him, and this was at level 25. He bashed me two times and I was dead. Dagger spec's haven't really gained a lot in the low levels either.