Playing down a Bonewall is like playing down 7 shields
And it shouldn't be as that breaks the rules.
Lets just say for 1 moment, that I agree with you, which I dont.
I play a bone wall. Yay. I block one of my enemies attacks. Worst Shield Ever. Unless I play a RoF with it, but then to get any use I need at least a duo deck, and 5

+ 5

so 10 quanta for a shield. Which makes it the most worthless card in the world.