Are really smart people less likely to care about being successful?

The opposite.

The smarter one is, the more one knows how precious life is and how hard one must therefore push oneself while one still has it.

A smart person may not have the same conception of success as a dumb person, and this could conceivably make it seem that the smart person’s intelligence drained him of ambition.

But if a smart person lacks ambition, that is despite his intelligence, not because of it.

In fact, smart people lack ambition only when they are damaged in some way.