Much as I love Star Trek, I wish they would take on deeper moral questions. As far as cultural (non-political) conflict, the deepest questions seem to be whether you prefer a Klingon bed or a fluffy Starfleet one, or whether you prefer Oo-mox to par’Mach.
Alien customs are either transparently bad or vapidly liberal.
You also have to think that human culture would change somewhat in the next few hundred years. I wish they’d do something with that.