"I also wonder a lot of times why many people don't have the drive for (self)-optimization. Maybe it is laziness, or perhaps they lack passion for what they do? I honestly don't know. I have, once or twice, asked someone with that behavior. The only answer I get is that they themselves don't know. Since it is a very personal topic, it might only be the diplomatic answer to a somewhat offensive question, no matter how nicely you formulate it.