Seth-Its not about the differance in the threads-------its about where the threds are screwed into the tube--------the failure will occur at the end of the threaded shank of the tie rod end in the tube-you are going from a solid amount of material to a thin tube that is weakened by the internal threads and that will create a weaker spot where the external forces on the link will cause the failure--------

The tapered shank in a correctly tapered receiving hole will actually fit up better than just a bolt in single shear mount--