"well-rounded" CAN mean being good at two or three things, it doesn't mean that everyone should attempt to be a polymath.

Also, the point of being "well-rounded" wasn't to excel at all activities, but by not totally subsuming yourself in one activity you might achieve a broader perspective about experiencing life.

Considering the question in the OP, it is funny you brought up Einstein, Musk, and Jobs in your reply.