Earlier quoted context omitted.
They had a lot to do during winter, though, cause it was a society with subsistence economy.
If 30-40k timelines are right that's way before agriculture and any kind of "economy". It's firmly hunter-gatherers and there's not much of that to do when it's after sunset.
Nobody says they couldn't find a time to do carving (existence of the artifact shows they could). The issue in question is comparative value of the time spent on it. Hunting, gathering and concomitant works were certainly both physically and mentally very demanding activities, and their way of life required thoughtful spending of energy. Consequently, whatever irregular pastime they had should have to be extremely valuable. It makes 'toy theory' somewhat unconvincing.