The WIMP "miracle" is often used to motivate WIMPs: that a WIMP with a weak-scale mass naturally freezes out of thermal equilibrium after the big bang with the right relic abundance. I understand the "weakly-interacting" part of the "miracle" -- the SM includes a weak interaction cross section -- but I don't understand why the "weak-scale mass" is such a coincidence. It would only be a coincidence if we had a generic independent reason to expect particles at the weak-scale. Do we? 100 GeV doesn't seem to be intrinsic to weakly-interacting particles (after all, neutrinos are weakly interacting, and they are pretty far from 100 GeV).
EDIT: adding two sources that seem to conflict each other to help explain the source of my confusion.
On page 9 of this paper Feng tells us that the thermal relic density is proportional to m^2/G^4, where m is the WIMP mass and G it's self-coupling. So the WIMP miracle only works for ~100 GeV particles with weak coupling.
But on page 221 of this paper by Jungman et al, we are told that the thermal relic density is independent of WIMP mass.
Both these papers are by experts in the field and are fairly authoritative. So my question is who is right? Or are both right and what am I misunderstanding?