We don't have an alternate history without Spock to compare to, so I reserve the right to doubt that it would have made any difference whether Spock would have

We don't have an alternate history without Spock to compare to, so I reserve the right to doubt that it would have made any difference whether Spock would have existed at all. If not this book, then they would've used other excuses. Everyone likes to do things 'their way'. Only those motivated to be good or better at something go out of their way to read, learn and change. Most people aren't motivated to be better at parenting, because they think they are already doing a good job. Isn't Johnny smiling, crawling, talking, walking, potty trained, ... when he should?