Kirk: Tarsus 4.
Spock: bullied, estranged paternal relationship. "So human. "
McCoy: divorced.
Comics had more tragedies for Scotty and McCoy.
Picard: estranged paternal relationship.
Riker: estranged paternal relationship.
Wesley: dad died.
Worf: bullied, fearful of his strength.
Geordi: born blind.
Chakotay: strained paternal relationship.
Tuvok: emotional dysregulation as a child.
Paris: strained emotional relationship with his dad.
B'elanna: divorced parents, bullied,
This is not new.
Also, another theme is being an outcast or feeling like an outsider with one's own people, but finding a new home and connections in a new community. That's a recurring theme that's there all the way back to Spock.
At one point in
Deep Space Nine, I believe Worf, Odo, Garak and Quark have ALL been formally disowned by their own cultures simultaneously. In addition, the series begins with Sisko feeling alienated from Starfleet and considering resigning, Bashir is hiding a secret that makes him different from everyone else, and Nog sees the flaws in Ferengi society and decides to assimilate Federation values.
I've heard this theme is one of the reasons the franchise has been popular with members of the LGBTQ community. Not only is an underlying theme of
Star Trek "
it gets better," but also the idea and hope of community where the different can find friends and a place to build a new family even when their own one doesn't want them.
From
Futurama's "Where No Fan Has Gone Before":
LEELA: You can't go to Omega 3; it's forbidden! I forbid you!
FRY: But we have to! The world needs Star Trek to give people hope for the future.
LEELA: But it's set 800 years in the past!
BENDER: Yeah, why is this so important to you?
FRY: 'Cause it-it taught me so much. Like how you should accept people, whether they be black, white, Klingon or even female. But most importantly, when I didn't have any friends, it made me feel like maybe I did.