It's an important story to tell, and I think your dismissals are indicative of the same flaw as the characters: thinking the petty struggles they face are more important than the survival of the species.

It's a flaw of these characters, and also of the contemporary society. There's a kind of distance towards "petty struggles" of everyday life that I'd consider a part of being mature.

Related: this is why I like science-fiction, especially the older one that's written/directed by people who focus on ideas, and not people. I hate the modern critique of sci-fi that characters are "flat". If I wanted to read about character development, petty squabbles and love affairs, I'd pick literally any other genre.

I don't think that they're mutually exclusive. Much of the sci‑fi and fantasy I've enjoyed over the years does both.

Certainly there's more tolerance for flat characters in sci‑fi than in other genres because you can focus on ideas, I agree with that.

But if all the characters in your story are flat, it does impact the quality. You can have good sci‑fi with flat characters, but great sci‑fi requires both interesting ideas and interesting characters. (And that's not quite enough either, but that's a tangent we don't need to get into)