I can not stress enough that in Star Trek, Amanda Grayson being an incredibly loving wife AND shitty parent is a feature, not a bug. She loves Sarek with her whole heart. And as much as she loves Spock, every single time she has to choose between them, she'll back Sarek. Spock grew up knowing his mom loved him, but that she also did not understand him and would never have his back.
Before people in the mainstream even had the vocabulary to describe what they were seeing, they understood on a gut level that Spock was a neurodivergent, mixed race adult son of two incredibly charismatic and successful parents.
There are so many layers of relatability here.
A surprising lot of people in very loving and devoted marriages aren't great parents. An unsurprising lot of powerful people with prestigious careers also aren't great parents.
Folks who grew up with parents who were great at their jobs and devoted to one another but who just couldn't relate to or understand their kids could see themselves in Spock. Moreover, he demonstrated that if they took a path radically different from what their parents wanted, they could become incredibly successful and even well liked in a whole different sphere.
Most of all, for folks who could see how much their parents adored one another but never felt like that love extended to them, there is something profound in the way Kirk looks at Spock like he hangs the stars in the sky. He's a source of hope that even if you grew up as your family's ugly duckling, if you get out from under their influence you can find someone who will perceive you as a swan.