What a great question! Thanks for asking me; I’ve been thinking about it for some days, and I also asked some of my fan friends from way back to get their memories on the subject.
When I returned to fandom after 25 years and started reading modern fan fic on AO3, I noticed how much the Tarsus tragedy is infused into Jim’s being, his character. It’s my memory, and my friends concur, that this came up in an occasional story back in the 70s, but it was not much written about nor did it shape Jim’s character the way it often does now.
I’ve been puzzling over this difference in how fandom, 40 years apart, views this incident so differently. The best I can come up with is that society’s attitudes and understanding have changed dramatically in the intervening years.
In the 70s we, as a society, were so much less informed and aware of how trauma can affect a person’s psyche. That shows in how badly Vietnam veterans were treated: they were generally considered to be “malingering” when they came home with PTSD (which was not a term we had in our vocabulary yet). They were criticized and marginalized, because society then thought it unmanly to be so affected by trauma. A sad and shameful part of our history.
I find it very interesting to read the newer fiction and see how a younger generation allows Jim to be human, not just some outdated ideal of a “real man.” I like how he is treated with more tenderness. I know it does not appeal to everyone of my generation, but I like it. And I love that younger people still care enough about Jim and his cohorts to want to write new fan fic, giving a new understanding of these characters, one that is true to their (your?) own worldview and experience.