Your torus grid layer consists of 5 disjoint grids. Those sections match up quite well with each-other to give the impression that they are joined, but topologically they intersect. The Boolean modifier chokes on self intersecting meshes.
Do you really need this grid to be hollow tubes, it's not a hollow tube in reality - worth considering that as a way to make the operation a little lighter processing wise.
The best geometry for the boolean is geometry that has no intersections, no double vertices. This means you must spend more time making such a grid, perhaps a script is the way to go.
You can see in the closeup that your geometry isn't as clean as you think.
If this answers the 'why' to your Boolean misfortune, perhaps the real question should be how to make such a grid to your exact specs.