I thought it was well understood that the most likely thing is just different physics we can't measure or predict? And in a quantum-mechanics type agnosticism we decided things that aren't measurable aren't worth trying to understand.
What's interesting about Kerr's work here is that he is arguing that singularities aren't the solution even purely within GR. If he's right, we can do away with singularities even before we figure out how gravity works at the quantum level. It'd be a pretty significant coup vs. the current line of thinking.
It's all well above my level of understanding, but Kerr is the man who solved the field equation in a way that predicted spinning black holes, long before we had discovered any, so it seems feasible to me he could be right.