Prior to becoming an engineer, I used to pour concrete (workers tend to call it 'crete), slabs (workers tend to call this flat work), footings and walls (workers tend to call vertical work "walls" regardless of the end use).
We always used tied bars for walls and footings, because you can't readily - or at all - manuever steel within walls and footing during a pour. So there is no practical way to remedy the problems cited above.
But we always used WWF for flat work, we walked right on it, with inspectors present or not. There were always long hooks on hand; yes, they had a name; no, I don't remember it. A senior laborer was always charged with pulling the mesh back up into the 'crete during the pour, as we were raking when it fell off the blocks. I never remember any inspectors - or owners, who often pop it during large $$$ projects - objecting.
The fact that the same type of steel was always used in certain types of work would indicate to me that: 1) cost is pretty comparable, and 2) the functionality of placing it in a certain application was the deciding factor.
Engineering is the practice of the art of science - Steve