Agreed. While I too want to see Chekhov's Starship fired, I find the character stuff quite fun. And while "lighthearted fun" is, well, fun, it is just a little snack compared to the meatier drama that a darker series can provide.
Science Fiction, as a literary form, has recently been more about human beings in extraordinary situations, and how being in those situations changes the humans in question. TV Sci Fi, in the past, was about the extraordinary situations themselves, and how they work, rather than about the people inside those Situations (This is a MASSIVE overgeneralization, and accordingly, not really true).
Now, in the last few years, TV SF has caught up to literary SF, and stay away from techity tech stuff. As a result, the writers have more opportunities to write about the things that writers find interesting, which (unsurprisingly), is people. And since happy people make for bad drama, we get something darker.
In a few years, we might see a rebound of "lighter" shows, but for now, character drama it is.