"I am not less ambitious. But I am also ambitious about being a great dad." Or Mom. This is a powerful mindset right here. It's also hard to judge someone's ambition from the outside because there is still so much inequality of opportunity. The OP mentioned limitations of Einstein, Steve Jobs, and Elon Musk as parents. The story of Paul Ehrenfest is an even more depressingly stark contrast between personal and professional success.

On the other hand, there is a lot of moral ambiguity when it comes to judging someone else's parenting - and lack of ambition clearly does not make one a better parent. The history of women in science and mathematics and literature illustrates the tradeoffs among talent and opportunity and ambition that have persisted for centuries and continue to this day. Two of my favorite examples are that of George Eliot (Mary Ann Evans), who was supported in her studies because her father considered her lacking in beauty and Emmy Noether (referred to as essentially the most intelligent woman of all time by Einstein), who demonstrated no prodigious talent in her early education but due to persistent and opportunities shaped in part by having a father who was an Algebraist, is remembered as an intellectual giant.