> It seems physicists just don't like there being two separate models, one for large things and one for small things, but it could be the universe is just like that, right?
No, it couldn't be just like that. There could exist a common umbrella theory that uses GR for certain objects and QM for others, but it would have to be a new theory that introduces a very important new info: the nature of the separation between the two.
Right now, all of the laws of QM say that it applies just as much to the motion of the Sun as to the motion of an electron. GR says the same. And yet, GR's predictions for how an electron behaves are clearly wrong. QM's predictions for how the Sun moves are closer to being correct (that is, QM + SR + Newtonian gravity), but it is hard to measure.
A unified theory has to either correct the equations of QM, GR, or both; or to add explicit boundaries to each of them. A theory that would say "an object moves according to the laws of QM if it's 0.00000001g or lower, and according to the laws of GR if it's any higher" (or any other distinguishing characteristic) would be an entirely new theory.
Interestingly, this new theory being proposed in the articles actually does something slightly in this vein: it says "QM applies to the electromagnetic, weak, and strong interactions, and GR applies to the mass/gravity interaction". It then finds a new way to account for the known inconsistencies between the math of each, apparently by getting rid of the assumption that a particle has a fixed mass (and thus fixed space-time curvature in GR).