I don't agree. Q, in his own way, actually does care.
As has been pointed out, Q did this to teach Picard and crew a lesson. If Q resurrects the people who died, then
that lesson means nothing. Q wants the crew to know that their actions have consequences, their missions have risks, and none of that means anything if Q can simply reverse everything whenever he's asked to do so.
It's like asking why Q didn't resurrect Robert and René after their deaths in
Generations. I don't think Q actually
wants Picard to suffer, but at the same time, Q doesn't want Picard to depend on Q bringing back everyone in his life who happens to die (for whatever reason). The sad fact is, life has risks. People die. And the survivors hurt. But this hurt is an important part of us, it can't just be taken away with the wave of a magic wand.
Remember Kirk in ST V - "I don't want my pain taken away. I NEED my pain." Same story here. I honestly think that if Q had resurrected those crew who died in "Q Who" (or Robert and René in GEN), it would have caused more damage than simply letting events play out as we saw them.