Hold on there. I'm not saying that folks are ignorant who claim that the holes will weaken the frame. I agree with those folks. The holes will weaken the frame.

The ignorance I refer to is in understanding the magnitude of effect. Without significant amounts of analysis, and maybe even using multiple frames, both drilled, and not drilled, tested to destruction in a dynamic tester, I'm not sure that I'd care to quantify just how much frame life has been lost.

Even if you wanted to do an FEM stress analysis, or even a fatigue test in an Instron axial-torsion, you'd need the exact hole diameter and placement, thread size (and whether the hole was drilled for 60, 70, or 75% threads, and whether the threads were formed or cut), frame size, weight of racks, and so forth. Of these details, I suspect we are all ignorant.